MUSHROOMS:
How to Grow Them.

A PRACTICAL TREATISE
ON
Mushroom Culture for Profit and Pleasure.

BY

WILLIAM FALCONER.

ILLUSTRATED.

NEW YORK,
ORANGE JUDD CO.
1892.

Entered, according to Act of Congress, in the year 1891, by the
ORANGE JUDD COMPANY,
In the Office of the Librarian of Congress, at Washington.

PREFACE

Mushrooms and their extensive and profitable culture should concern every one. For home consumption they are a healthful and grateful food, and for market, when successfully grown, they become a most profitable crop. We can have in America the best market in the world for fresh mushrooms; the demand for them is increasing, and the supply has always been inadequate. The price for them here is more than double that paid in any other country, and we have no fear of foreign competition, for all attempts, so far, to import fresh mushrooms from Europe have been unsuccessful.

In the most prosperous and progressive of all countries, with a population of nearly seventy millions of people alert to every profitable, legitimate business, mushroom-growing, one of the simplest and most remunerative of industries, is almost unknown. The market grower already engaged in growing mushrooms appreciates his situation and zealously guards his methods of cultivation from the public. This only incites interest and inquisitiveness, and the people are becoming alive to the fact that there is money in mushrooms and an earnest demand has been created for information about growing them.

The raising of mushrooms is within the reach of nearly every one. Good materials to work with and careful attention to all practical details should give good returns. The industry is one in which women and children can take part as well as men. It furnishes indoor employment in winter, and there is very little hard labor attached to it, while it can be made subsidiary to almost any other business, and even a recreation as well as a source of profit.

In this book the endeavor has been, even at the risk of repetition, to make the best methods as plain as possible. The facts herein presented are the results of my own practical experience and observation, together with those obtained by extensive reading, travel and correspondence.

To Mr. Charles A. Dana, the proprietor of the Dosoris mushroom cellars and estate, I am greatly indebted for opportunities to prepare this book. For the past eight years everything has been unstintedly placed at my disposal by him to grow mushrooms in every way I wished, and to experiment to my heart's content.

To Mr. William Robinson, editor of The Garden, London, I am especially indebted for many courtesies—permission to quote from The Garden, "Parks and Gardens of Paris," and his other works, and to illustrate the chapters in this book on Mushroom-growing in the London market gardens and the Paris caves, with the original beautiful plates from his own books.

The recipes given in the chapter on Cooking Mushrooms, except those prepared for this work by Mrs. Ammersley, although based on the ones given by Mr. Robinson, have been considerably modified by me and repeatedly used in my own family.

My thanks are also due to Mr. John F. Barter, of London, the largest grower of mushrooms in England, for information given me regarding his system of cultivation; to Mr. John G. Gardner, of Jobstown, N. J., one of the most noted growers for market in this country, for facilities allowed me to examine his method of raising mushrooms; and to Messrs. A. H. Withington, Samuel Henshaw, George Grant, John Cullen, and other successful growers for assistance kindly rendered.

WILLIAM FALCONER.
Dosoris, L. I., 1891.

TABLE OF CONTENTS

ILLUSTRATIONS

MUSHROOMS, HOW TO GROW THEM.

CHAPTER I.

THOSE WHO SHOULD GROW MUSHROOMS.

Market Gardeners.—The mushroom is a highly prized article of food which can be as easily grown as many other vegetable products of the soil—and with as much pleasure and profit. Below it is shown, in particular, that this peculiar plant is singularly well adapted to the conditions that surround many classes of persons, and by whom the mushroom might become a standard crop for home use, the city market, or both. It is directly in their line of business; is a winter crop, requiring their care when outdoor operations are at a standstill, and they can most conveniently attend to growing mushrooms. They have the manure needed for their other crops, and they may well use it first for a mushroom crop. After having borne a crop of mushrooms it is thoroughly rotted and in good condition for early spring crops; and for seed beds of tomatoes, lettuces, cabbages, cauliflowers, and other vegetables, it is the best kind of manure.

Years ago market gardening near New York in winter was carried on in rather a desultory way, and the supply of salads and other forced vegetables was limited and mostly raised in hotbeds and other frames, and prices ran high. But of recent years our markets in winter have been so liberally supplied from the Southern States, that, in order to save themselves, our market gardeners have been compelled to take up a fresh line in their business, and renounce the winter frames in favor of greenhouses, and grow crops which many of them did not handle before. These greenhouses are mostly long, wide (eighteen to twenty feet), low, hip-roofed (30°) structures. In most of them the salad beds are made upon the floor, and the pathways are sunken a little so as to give headroom in walking and working. Others of these greenhouses are built a little higher, and middle and side benches are erected within them, as in the case of florists' greenhouses, and with the view of growing salad plants on these benches as florists do carnations, and mushrooms under the benches. The mushrooms are protected from sunlight by a covering of light boards, or hay, or the space under the benches is entirely shut in, cupboard fashion, with wooden shutters. The temperature is very favorable for mushrooms,—steady and moderately cool, and easily corrected by the covering-in of the beds; and the moisture of the atmosphere of a lettuce house is about right for mushrooms. In such a house the day temperature may run up, with sunshine, to 65° or 70° in winter, but an artificial night temperature of only 45° to 50° is maintained. Under these conditions, with the beds about fifteen inches thick, they should continue to yield a good crop of short-stemmed, stout mushrooms for two or three months, possibly longer.

Besides growing the mushrooms in greenhouses our market gardeners are very much in earnest in cultivating them in cellars. Some of these cellars are ordinary barn cellars, others—large and commodious—have been built under barns and greenhouses, purposely for the cultivation of mushrooms. Several of these mushroom cellars may be found on Long Island between Jamaica and Woodhaven.

Florists.—In midwinter the cut flower season is at its height and the florist endeavors to make all the money out of his greenhouses that he possibly can; every available inch of space exposed to the light is occupied by growing plants, and under the benches alongside of the pathways dahlias, cannas, caladiums, and other tubers and bulbs are stored, also ivies, palms, succulents and the like. In order that the plants may be more fully exposed to the sunlight, they are grown on benches raised above the ground so as to bring them near to the glass; and the greenhouse seems to be full to overflowing. But right here we have the best kind of a mushroom house. The space under the benches, which is nearly useless for other purposes, is admirably adapted for mushroom beds, and the warmth and moisture of the greenhouse are exceptionally congenial conditions for the cultivation of mushrooms. Florists need the loam and manure anyway, and these are just as good for potting purposes—better for young stock—after having been used in the mushroom beds than they were before, so that the additional expense in connection with the crop is the labor in making the beds and the price of the spawn. Mushrooms are not a bulky crop; they require no space or care in summer, are easily grown, handled, and marketed, and there is always a demand for them at a good price. If the crop turns out well it is nearly all profit; if it is a complete failure very little is lost, and it must be a bad failure that will not yield enough to pay for its cost. Why should the florist confine himself to one crop at a time in the greenhouse when he may equally well have two crops in it at the same time, and both of them profitable? He can have his roses on the benches and mushrooms under the benches, and neither interferes with the other. Let us take a very low estimate: In a greenhouse a hundred feet long make a five foot wide mushroom bed under the main bench; this will give 500 square feet of bed, and half a pound to the foot will give 250 pounds of mushrooms, which, sold at fifty cents a pound net, brings $125. This amount the florist would not have realized without growing the mushrooms.

Private Gardeners.—It is a part of their routine duty, and success in mushroom growing is as satisfactory to themselves as it is gratifying to their employers. Fresh mushrooms, like good fruit and handsome flowers, are a product of the garden that is always acceptable. One of the principal pleasures in having a large garden and keeping a gardener consists in being able to give to others a part of the choicest garden products.

In most pretentious gardens there is a regular mushroom house, and the growing of mushrooms is an easy matter; in others there is no such convenience, and the gardener has to trust to his own ingenuity where and how he is to grow the mushrooms. But so long as he has an abundance of fresh manure he can usually find a place in which to make the beds. In the tool-shed, the potting-shed, the wood-shed, the stoke-hole, the fruit-room, the vegetable-cellar, or in some other out-building he can surely find a corner; or, handier still, convenient room under the greenhouse benches, where he can make some beds. Failing all of these he can start in August or September and make beds outside, as the London market gardeners do.

In fruit-forcing houses, especially early graperies, gardeners have a prejudice against growing any other plants than the grapevines lest red spiders, thrips, or mealy bugs are introduced with the plants, but in the case of mushrooms no such grounds are tenable. As the vines have yielded their fruit by midsummer and ripened their wood early so as to be ready for starting into growth again in December or January, the grapery is kept cool and ventilated in the fall and early winter, but this need not interfere with the mushroom crop. Box up the beds or make them in frames inside the grapery; the warm manure will afford the mushrooms heat enough until it is time to start the vines, when the increased temperature and moisture of the house will be in favor of the mushrooms because of the declining heat in the manure beds. The mushrooms have no deleterious effect whatever upon the vines, nor have the vines upon the mushrooms.

Village People and Suburban Residents.—Those who keep horses should, at least, grow mushrooms for their own family use and, if need be, for market as well. They are so easily raised, and they take up so little space that they commend themselves particularly to those who have only a village or suburban lot, and, in fact, only a barn. And they are not a crop for which we have to make a great preparation and need a large quantity of manure. No matter how small the bed may be, it will bear mushrooms; and if we desire we can add to the bed week after week, as our store of manure increases, and in this way keep up a continuous succession of mushrooms. A bed may be made in the cow-house or horse-stable, the carriage-house, barn-cellar, woodshed, or house-cellar; or if we can not spare much room anywhere, make a bed in a big box and move it to where it will be least in the way. But the best place is, perhaps, the cellar. An empty stall in a horse-stable is a capital place, and not only affords room for a full bed on the floor, but for rack-beds as well.

Farmers.—No one can grow mushrooms better or more economically than the farmer. He has already the cellar-room, the fresh manure and the loam at home, and all he needs is some spawn with which to plant the beds. Nothing is lost. The manure, after having been used in mushroom beds, is not exhausted of its fertility, but, instead, is well rotted and in a better condition to apply to the land than it was before being prepared for the mushroom crop. The farmer will not feel the little labor that it takes. There is no secret whatever connected with it, and skilled labor is unnecessary to make it successful. The commonest farm hand can do the work, which consists of turning the manure once every day or two for about three weeks, then building it into a bed and spawning and molding it. Nearly all the labor for the next ten or twelve weeks consists in maintaining an even temperature and gathering and marketing the crop.

Many women are searching for remunerative and pleasant employment upon the farm, and what can be more interesting, pleasant and profitable work for them than mushroom-growing? After the farmer makes up the mushroom bed his wife or daughter can attend to its management, with scarcely any tax upon her time, and without interfering with her other domestic duties. And it is clean work; there is nothing menial about it. No lady in the land would hesitate to pick the mushrooms in the open fields, how much less, then, should she hesitate to gather the fresh mushrooms from the clean beds in her own clean cellar? Mushrooms are a winter crop; they come when we need them most. The supply of eggs in the winter season is limited enough, and pin-money often proportionately short; but with an insatiable market demand for mushrooms all winter long, at good prices, no farmer's wife need care whether the hens lay eggs at Christmas or not. When mushroom-growing is intelligently conducted there is more money in it than in hens, and with less trouble.

CHAPTER II.

GROWING MUSHROOMS IN CELLARS.

Underground Cellars.—Mushrooms require a uniform moderately low temperature and moist atmosphere, and will not thrive where draughts, or sudden fluctuations of temperature or moisture prevail. Therefore an underground cellar is the best of all structures in which to grow mushrooms. The cellar is everybody's mushroom house.

Cellars are under dwellings, barns, and often under other out-buildings. These cellars are imperative for domestic purposes, for storing apples, potatoes and other root crops and perishable produce; and for these uses we need to make them frost proof and dry. These cellars are ideal mushroom houses, and any one who has a good cellar can grow mushrooms in it. In fact, our market gardeners who are making money out of mushrooms find it pays them to excavate and build cellars expressly for growing mushrooms. Indeed, some of our market gardeners who have never grown a mushroom or seen one grown, but who know well that some of their neighbors are making money out of this business, instinctively feel that the first step in mushroom-growing is a cellar. It is almost incredible how secretly the market growers guard everything in connection with mushroom-growing from the outside world, and even from one another; in fact, in some cases their next-door neighbors and life-long intimate friends have never been inside their mushroom cellars.

If a cellar is to be wholly devoted to mushroom-growing it should be made as warm as possible with double windows, and double doors, where the entrance is from the outside, but if from another building single doors will suffice. A chimney-like shaft or shafts rising from the ceiling should be used as ventilators in winter, when we can not ventilate from doors or windows; indeed, side ventilation at anytime when the beds are in bearing condition is rather precarious. There should be some indoor way of getting into the cellar, as by a stairway from the building above it. Also an easy way of getting in fresh materials for the beds, and removing the exhausted material. This is, perhaps, best obtained by having a door that opens to the outside, or a moderately large one from the building above.

Fig. 1. Mushroom Cellar under a Barn.

The interior arrangement of the cellar is a matter of choice with the grower, but the simplest way is to have beds three or four feet wide around the inside of the walls, and beds six feet wide, with pathways two, or two and one-half feet wide between them running parallel along the middle of the cellar. Above these floor-beds, shelf-beds in tiers of one, two, or three, according to the height of the cellar, may be formed, always leaving a space of two and one-half or three feet between the bottom of one bed and the bottom of the next. This is very necessary, in order to admit of making and tending the beds and gathering the crop, and emptying the beds when they are exhausted.

Provision should also be made for the artificial heating of these cellars, and room given for the heating pipes wherever they are to run. But wherever fire heat is used in heating these cellars, if practicable, the furnace itself should be boxed off, by a thin brick wall, from the main cellar, and the pipes only introduced. This does away with the dust and noxious gas, and modifies the parching heat.

But in a snug, warm cellar, artificial heat is not absolutely necessary. We can grow capital crops of mushrooms in such a cellar without any furnace heat, simply by using a larger body of material in making the beds,—enough to maintain a steady warmth for a long time. But this, observe, is a waste of material, for no more mushrooms can be grown in a bed two feet thick than in one a foot thick. In an unheated cellar the mushrooms grow large and solid, but they do not come so quickly nor in such large numbers as in a heated one. And a little artificial warmth has the effect of dispelling that cold, raw, damp air peculiar to a pent-up cellar in winter, and purifies the atmosphere by assisting ventilation.

Instead of using box beds, some growers spread the bed all over the floor of the cellar, and leave no pathway whatever, stepping-boards or raised pathways being used instead. Of course, in these instances, no shelf beds are used. Others make ridge beds all over the cellar floor, as the Parisians do in the caves. The ridges are two feet wide at bottom, two feet high, and six or eight inches wide at top, and there is a foot alley between them. Here, again, no shelf beds are used.

One of the chief troubles with flat-roofed mushroom cellars is the drip from the condensed moisture rising from the beds, and this is more apparent in unheated than in heated cellars,—the wet gathers upon the ceiling and, having no slope to run off, drips down again. Oiled paper or calico strung along Λ wise above the upper beds protects them perfectly; whatever falls upon the passage-ways upon the floor does no harm.

In any other outhouse cellar, as well as in one completely given over to this use, we can make up beds and grow good mushrooms. Mr. James Vick told me that at his seed farm near Rochester he raises many mushrooms in winter in his potato cellars; and so can any one in similar places. Mr. John Cullen, of South Bethlehem, Pa., a very successful cultivator, tells me that his present mushroom cellar used to be a large underground cistern, but with a little fixing, and opening a passage-way to it from a neighboring cellar, he has converted it into an excellent cellar for mushrooms, and surely the immense crops that I have seen in that cave of total darkness justify his good opinion of it.

In Dwelling House.—The cellar of a dwelling house is a capital place for mushroom beds, and can be used in whole or part for this purpose. In the case of private families who wish to grow a few mushrooms only for their own use it is not necessary to devote a whole cellar to it; but partition off a part of it with boards and make the beds in this. Or make a bed alongside of the wall anywhere and box it in to protect it from cold and draughts, and mice and rats. You can have shelves above it for domestic purposes, just as you would in any other part of the cellar. Bear in mind that mushrooms thrive best in an atmospheric temperature of from 50° to 60°, and if you can give them this in your house-cellar you ought to get plenty of good mushrooms. But if such a high temperature can not be maintained without impairing the usefulness of the cellar for other purposes, box up the beds tightly, and from the heat of the bed itself, when thus confined, there usually will be warmth enough for the mushrooms, but if not spread a piece of old carpet or matting over the boxing.

The beds may be made upon the floor, and flat, or ridged, or banked against the wall, ten or twelve inches deep in a warm cellar, and fifteen to twenty inches or more deep in a cool cellar, and about three feet wide and any length to suit.

Fig. 2. Boxed-up Frame with Straw Covering.

The boxing may consist of any kind of boards for sides and ends, and be built about six or ten inches higher than the top of the beds, so as to give the mushrooms plenty headroom; the top of the boxing may be a lid hung on hinges or straps, or otherwise arranged, to admit of being easily raised or removed at will, and made of light lumber, say one-half inch thick boards. In this way, by opening the lid, the mushrooms are under observation and can be gathered without any trouble. When the lid is shut they are secure from cold and vermin. Thus protected the cellars can be ventilated without interfering with the welfare of the mushrooms. A light wooden frame covered with calico or oiled paper would also make a good top for the boxing, only it would not be proof against much cold, or rats or mice. If desirable, in warm cellars, shelf beds could be built above the floor beds, but in cool, airy cellars this would not be advisable.

Manure beds in the dwelling-house cellar may seem highly improper to many people, but in truth, when rightly handled, these beds emit no bad odor. The manure should be prepared away from the house, and when ready for making into beds it can be spread out thin, so as to become perfectly cool and free from steam. When it has lain for two days in this condition it may be brought into the cellar and made into beds. Having been well sweetened by previous preparation, it is now cool and free from steam, and almost odorless; after a few days it will warm up a little, and may then be spawned and earthed over at once. Do not bury the spawn in the manure, merely set it in the surface of the manure; this saves the spawn from being destroyed by too great a heat, should the bed become unduly warm. This, if the manure has been well prepared, is not likely to occur. The coating of loam prevents the escape of any further steam or odor from the manure.

On the 14th of January last, Mr. W. Robinson, editor of the London Garden, in writing to me, mentioned the following very interesting case of growing mushrooms in the cellar of a dwelling house: "I went out the other day to see Mr. Horace Cox, the manager of the Field newspaper, who lives at Harrow, near the famous school. His house is heated by a hot-water system called Keith's, and the boiler is in a chamber in the house in the basement. The system interested me and I went down to see the boiler, which is a very simple one worked with coke refuse. However, I was pleased to see all the floor of the room not occupied by the boiler covered with little flat mushroom beds and bearing a very good crop. Truth to tell, I used to fear growing mushrooms in dwelling houses might be objectionable in various ways; but this instance is very interesting, as there is not even the slightest unpleasant smell in the chamber itself. The beds are small, scarcely a foot high, and perfectly odorless; so that it is quite clear that one may cultivate mushrooms in one's house, in such a case as this, without the slightest offence."

Mr. Gardner's Method.—Mr. J. G. Gardner, of Jobstown, N. J., uses an ordinary cellar, such as any farmer in the country has, and the little that has been done to it to darken the windows and make them tight, so as to render them better for mushrooms, any farmer with a hand-saw, an ax, a hammer and a few nails and some boards can do. Mr. Gardner is a market gardener, and has not the amount of fresh manure upon his own place that he needs for mushroom-growing, but he buys it, common horse manure, in New York, and it is shipped to him, over seventy miles, by rail. And this pays; and if it will pay a man to get manure at such a cost for mushroom-growing, how much more will mushroom-growing pay the farmer who has the cellar and the manure as well? Mr. Gardner raises mushrooms, and lots of them. When I visited him last November, instead of trying to hide anything in their cultivation from me, he took particular pains to show and explain to me everything about his way of growing them. And he assures me that by adopting simple means of preparing the manure and "fixing" for the crop, and avoiding all complicated methods, one can get good crops and make fair profits.

His cellar is sixty feet long, twenty-four feet wide, and nine feet high from floor to ceiling. The floor is an earthen one, but perfectly dry. It is well supplied with window ventilators and doors, and in the ceiling in the middle of the cellar opens a tall shaft or chimney-like ventilator that passes straight up through the roof above. While the beds are being made full ventilation by doors, windows and shaft is given, but as soon as there is any sign of the mushrooms appearing all ventilators except the shaft in the middle are shut and kept closed.

The bed occupies the whole surface of the cellar floor and was all made up in one day. As a pathway, a single row of boards is laid on the top of the bed, running lengthwise along the middle of the cellar from the door to the farther end, and here and there between this narrow path and the walls on either side a few pieces of slate are laid down on the bed to step upon when gathering the mushrooms. Here is the oddest thing about Mr. Gardner's mushroom-growing. He does not give the manure any preparatory treatment for the beds. He hauls it from the cars to the cellar, at once spreads it upon the floor and packs it solid into a bed. For example, on one occasion the manure arrived at Jobstown, July 8th; it was hauled home and the bed made up the same day, and the first mushrooms were gathered from this bed the second week in September,—just two months from the time the manure left the New York or Jersey City stables. The bed was fifteen inches thick. In making it the manure was first shaken up loosely to admit of its being more evenly spread than if pitched out in heavy forkfuls, and it was then tramped down firmly with the feet. The bed was then marked off into halves. On one half (No. 1) a layer of a little over three inches of loam was at once placed over the manure; on the other half (No. 2) no loam was used at this time, but the manure on the surface of the bed—about three inches deep—was forked over loosely. Twelve days after having been put in the temperature of the bed No. 2, three inches deep, was 90°, and then it was spawned. On the next day the soil from bed No. 1, spawned four days earlier, was thrown upon bed No. 2, and then part of the soil that was thrown on No. 1 was thrown back again on No. 2, so that now a coating of loam an inch and a half deep covered the whole surface of the bed. When finished the surface was tamped gently with a tamper with a face of pine plank sixteen inches long by twelve inches wide. Mr. Gardner does not believe in the alleged advantages of a hard-packed surface on the mushroom bed, but is inclined to favor a moderately firm one.

He uses the English brick spawn, which is sold by our seedsmen. He has tried making his own spawn, but owing to not having proper means for drying it, he has had rather indifferent success.

Almost all growers insert the pieces of spawn about two to three inches under the surface of the manure, one piece at a time, and at regular intervals of nine inches or thereabouts apart each way—lengthwise and crosswise. But here, again, Mr. Gardner displays his individuality. He breaks up the spawn in the usual way, in pieces one or two inches square. Of course, in breaking it up there is a good deal of fine particles besides the lumps. With an angular-pointed hoe he draws drills eighteen inches apart and two and one-half to three inches deep lengthwise along the bed, and in the rows he sows the spawn, as if he were sowing peach stones, or walnuts, or snap beans, and covers it in as if it were seeds.

Mr. Gardner regards 57° as the most suitable temperature for a mushroom house or cellar, and, if possible, maintains that without the aid of fire-heat. He has hot-water pipes connected with the contiguous greenhouse heating arrangement in his cellar, but he never uses them for heating the mushroom cellar except when obliged to. By mulching his bed with straw he gets along without any fire-heat, but this is very awkward when gathering the mushrooms.

After the bed has borne a little while it is top-dressed all over with a half-inch layer of fine soil. Before using, this soil has been kept in a close place—pit, frame, shed, or large box—in which there was, at the same time, a lot of steaming-hot manure, so that it might become thoroughly charged with mushroom food absorbed from the steam from the fermenting material.

Should any portion of the bed get very dry, water of a temperature of 90° is given gently and somewhat sparingly through a fine-spraying water-pot rose, or syringe. Enough water is never given at any one time to penetrate through the casing into the manure below or the spawn in the manure. But rather than make a practice of watering the beds, Mr. Gardner finds it is better to maintain a moist atmosphere, and thus lessen the necessity for watering.

Mr. Gardner firmly believes that the mushrooms derive much nourishment from the "steam" of fermenting fresh horse manure, and by using this "steam" in our mushroom houses we can maintain an atmosphere almost moist enough to be able to dispense with the use of the syringe, and the mushrooms are fatter and heavier for it. And he practices what he preaches. In one end of his mushroom cellar he has a very large, deep, open box, half filled with steaming fresh horse-droppings, and once or twice a day he tosses these over with a dung-fork, in order to raise a "steam," which it certainly does. It is also for this purpose that he introduces the loam so soon when making the beds, so that it may become charged with food that otherwise would be dissipated in the atmosphere.

There is a marked difference between the mushrooms raised from the French flake spawn and those from the English brick spawn, but he has never observed any distinct varieties from the same kind of spawn. Sometimes a few mushrooms will appear that are somewhat differently formed from those of the general crop, but this he regards as the result of cultural conditions rather than of true varietal differences.

His last year's bed began bearing early in November, and continued to bear a good crop until the first of May. After that time, no matter what the crop may be, the mushrooms become so infested with maggots as to be perfectly worthless, and they are cleared out. It is on account of the large body of manure in the bed, and the low, genial, and equable temperature of the cellar that the beds in this house always continue so long in good cropping condition.

Some years ago the mushrooms were not gathered till their heads had opened out flat, but nowadays the marketmen like to get them when they are quite young and before the skin of the frill between the cup and the stem has broken apart. A good market is found in New York, Philadelphia and Boston.

Mr. Denton's Method.—Mr. W. H. Denton, of Woodhaven, L. I., is an extensive market gardener about ten miles from New York. During the summer months he grows outdoor vegetables for the New York and Brooklyn markets, and in winter mushrooms in cellars. He has no greenhouses. Under his barns he has two large cellars which he devotes entirely to mushroom-growing in winter. The cellars are seven and one-half feet high inside; the beds five feet wide, nine inches deep, two feet apart, and run parallel to one another the whole length of the cellar. The beds are three deep, that is, one bed is made upon the floor, and the other two, rack or shelf fashion, are made above the floor bed, and two and one-half feet apart from the bottom of the one bed to the bottom of the one above it. The shelves altogether are temporary structures built of ordinary rough scantling and hemlock boards, and the beds are all one board deep.

A common iron stove and string of sheet iron smoke pipes are used for heating the cellars. But he tells me the parching effect is very visible on the beds, it dries them up on the surface very much, and he has to sprinkle them frequently with water to keep them moist enough. During the late summer and fall months, on his return trips from the Brooklyn markets, Mr. Denton hauls home fresh horse manure from the City stables. All that he can put on a wagon costs him about twenty-five cents; and this is what he uses for mushrooms. He prepares it in a large open shed just above the cellar, and when it is fit for use he adds about one-third of its bulk of loam. The loam is the ordinary field soil from his market garden. He tells me he has better success with beds made up in this way than when manure alone is used. We all know how very heavily market gardeners manure their land, also how vigorously most writers on mushroom culture denounce the use of manure-fatted loam in mushroom beds, but here is Mr. Denton, the most successful grower of mushrooms for market in the neighborhood of New York, practicing the very thing that is denounced! While he likes good lively manure to begin with he is very careful not to use it soon enough to run any risk of overheating in the beds. The loam in the manure counteracts this strong heating tendency, also with the loam mixture the shelf-beds can be built much more firmly than with plain manure on the springy boards. When the temperature falls to 90° he spawns the beds.

He uses both French and brick spawn, but leans with most favor to the latter, of which in the fall 1889 he used 400 lbs. He markets from 1700 to 2500 lbs. of mushrooms a year from these two cellars. Mr. Denton believes emphatically in cleanliness in the mushroom cellar, and ascribes his best successes to his most thorough cleaning. Every summer he cleans out his cellars and limewashes all over.

Mr. Van Siclen's Method.—Mr. Abram Van Siclen, of Jamaica, L. I., also grows mushrooms very extensively in underground cellars, whose arrangements do not differ materially from those of Mr. Denton's, except in his manner of heating. He runs an immense greenhouse vegetable-growing establishment, as well as a summer truck farm, and uses hot water heating apparatus, also smoke flues as employed ordinarily in greenhouses, especially lettuce houses. The sheet iron pipes, except in squash houses, he does not hold in much favor.

Fig. 3. Cross-section of the Dosoris Mushroom Cellar.

The Dosoris Mushroom Cellar.—This is a subterranean tunnel or cellar that was excavated and arched some ten years ago, expressly for the cultivation of mushrooms. It is situated in an open, sunny part of the garden, and its extreme length from outside of end walls is eighty-three feet; but of this space nine feet at either end are given up to entrance pits and a heating apparatus; and the full length of the mushroom cellar proper inside the inner walls is sixty-three feet. The walls and arch are of brick, and the top of the arch is two and one-half feet below the surface of the soil. This tunnel or arch is seven feet high in the middle and eight feet wide within, but a raised two-feet-wide pathway along the middle lessens the height to six and one-half feet. Between this pathway and the sides of the building there is only an earthen floor, but it is quite dry, as the cellar is perfectly drained. Three ventilators sixteen feet apart had been built in the top of the arch, but this was a mistake, as the condensation in the cellar in winter from these ventilators always keeps the place under them cold and wet and rather unproductive. One tall wooden chimney-like shaft would have been a better ventilator than the three ventilating holes now there, which are covered over with an iron and glass grating.

Fig. 4. Ground Plan of the Dosoris Cellar.

At one end of the house and behind the stairs descending into the pit is the heating apparatus, from which a four-inch hot-water pipe passes around inside the house near the wall and only four inches above ground. A three-feet wide hemlock flooring for the bed to rest on is laid along each side and about four inches above the pipe, leaving the aperture between the earth floor and the bottom of the bed along the pathway open for the escape of the artificial heat. One might think that the hot water pipe under, and so near the bed, would dry it up and destroy it, but such is not the case. In a cellar of this kind very little fire heat is needed to maintain the required temperature, and I do not know where else the pipes could be put where they would do the work any better and be more out of the way.

These beds, for convenience in building them, spawning them, molding them over, gathering the crop and watering the beds, and removing the manure after the beds are exhausted, are built against the wall and with a rounded face, thus giving a three and one-half feet wide surface of bed in place of one three feet wide, were it built flat. This gain in superficial area is not so important as it might seem, for the part immediately next to the edge of the pathway seldom yields very much. Above these beds a string of shelf beds is arranged which runs the full length of both sides of the cellar. From the floor of the under bed to the floor of the top bed is three feet, and the upper beds are just as wide as the lower ones. The shelves for the beds are temporary affairs, put up and taken down every year. The cross-bars rest in sockets in the wall made by cutting out half a brick every four feet along the wall, and on upright strips or feet one and one-fourth by four inches wide, or two by three inches, set under the inside ends of the cross-bars and resting on the cement floor close up against the lower bed. By having this foot end a quarter of an inch higher than the wall end the heavy weight of the bed is thrown toward the wall. Loose hemlock boards set close together form the flooring, for there is no need of nailing any of them except the one next to the upright face board, which is ten inches wide, and nailed along the front, by the pathway, to the posts and shelf board. By tilting the weight to the wall the upright board is firm enough to hold its place against any pressing out in building the beds. The supporting legs of the shelves are also nailed to the face board of the lower bed, and this holds them perfectly solid in place. The shelf beds are eight inches deep at front, but can be made of any depth desired against the walls at the back. The cold wall has no injurious effect upon the bearing of the bed, and many fine mushrooms grow close against the walls.

The entrance pits are nine and one-half feet deep from ground level, three feet eight inches wide, nine feet long, and are covered over with folding doors on strong hinges, and descended into by means of wooden movable stairs. These dimensions are needed at the end where the heating apparatus is placed, but at the other end, although it is convenient in handling the manure, a space two or three feet less would have answered just as well. A close door at either end of the mushroom cellar proper separates it from the end pits. The cellar is divided in the middle by a partition. This gives, when it is in full working order, eight beds, each thirty-one and one-half feet long, or a continuous run of 252 feet or 756 square feet of surface, and as the beds are renewed twice a year this gives 504 running feet of bed, or 1512 square feet of surface. A common average crop is three-fifths of a pound of mushrooms to the square foot of bed, and a good fair average is four-fifths of a pound. This would give over a thousand pounds of mushrooms a season from this cellar when it is in full running capacity. But as the aim is to have a steady supply of mushrooms from October until May, and not a flush at any one time and a scarcity at another, only two beds are made at a time, allowing a month to intervene between every two.

For the two beds, No. 1, preparing the manure begins in July, the beds are made up in August, and gathering of the crop commences in October; work on the two beds, No. 2, begins in August, the beds are made up in September, and the mushrooms gathered in November; preparing for the two beds, No. 3, begins in September, the beds are made up in October, gathering commences in December; for the two beds, No. 4, work begins in October, the beds are made up in November, and the crop is gathered in January; for the two beds, No. 5 (No. 1 renewed), work begins in November, the beds are made up in December, and the crop is gathered in February; for the two beds, No. 6 (No. 2 renewed), work begins in December, the beds are made up in January, and the crop is gathered in March; for the two beds, No. 7 (No. 3 renewed), work begins in January, the beds are made up in February, and the crop is gathered in April; for the two beds, No. 8 (No. 4 renewed), work begins in February, the beds are made up in March, and the mushrooms gathered in May. After this time of year the summer heat renders mushroom-growing uncertain, and the maggots destroy the mushrooms. This system allows each bed a bearing period of two months. After yielding a crop for some seven to nine weeks the beds are pretty well exhausted and hardly worth retaining longer. They might drag along in a desultory way for weeks, but as soon as they stop yielding a paying crop we clear them out and start afresh.

And when the mushroom season is closed we lift out and remove the manure, clean the boards used in shelving, and give the cellar a thorough cleaning,—whitewash its walls and paint its woodwork with kerosene to destroy noxious insects and fungi.

Fig. 5. Base-burning Water Heater.

Fig. 6. Vertical Section.

The heating apparatus consists of one of Hitchings' base-burner boilers with a four-inch hot-water pipe that passes around inside the cellar, and it deserves special mention because of its economy, efficiency, and the satisfaction it gives generally. This boiler needs no deep or spacious stoke-hole. Here it is set under the stairway in a pit four and one-half feet long, by three feet wide, by eighteen inches deep; it is not in the way, and there is plenty of room to attend to it. The heater, like a common parlor stove, has a magazine for the supply of coal. It has a double casing with the water space between and down to the bottom of it, so that when set in a shallow pit there is no difficulty whatever about the circulation of the water in the pipes. The hot water passes from the boiler to an open iron tank placed two feet above it, as shown in the engraving, and thence down through a perpendicular pipe till it reaches and enters the horizontal pipes that pass around the cellar and, returning, enters the boiler again near its base. The boiler and pipes are filled from this tank, which should always be kept at least half full of water, and looked into every day when in use, so that when the water gets lower than half full it may be filled up again. About 134 running feet of four-inch pipe are included inside the cellar (sixty-four feet on each side and six feet across at further end); this gives 134 square feet of heating surface, or a proportion of about a square foot of heating surface for every fifteen cubic feet of air space in the cellar. This proportion is more than ample in the coldest weather, but beneficial in so far that there is no need to fire hard to maintain the proper temperature. A three-inch pipe would have given heat enough, but the heat would not have been so steady. Both nut and stove coal is used in this heater, and in the severest winter weather it burns not more than a common hodful in twenty-four hours. It is so easily regulated that the temperature of the cellar day or night, or in mild or severe weather, never varies more than three degrees, namely from 57° to 60°.

In a close underground cellar where the temperature in midwinter without any artificial heat does not fall below 40° or 45° it is an easy matter, with such a heater as this is, to maintain any desired temperature. If the grates are renewed now and then, the heater should last in good condition for twenty years. With the ordinary stove there is danger of fire, of escaping gas and of sudden changes of temperature, and the evil influence of a dry, parching heat—just what mushrooms most dislike—is ever present. The first cost of a hot water apparatus may be more than that of an old stove and sheet iron pipes, but where mushrooms are grown extensively, as a matter of economy, efficiency, and convenience, the advantages are altogether on the side of the hot water apparatus. Furthermore, hot water pipes can be run where it would be unsafe to put smoke pipes.

CHAPTER III.

GROWING MUSHROOMS IN MUSHROOM HOUSES.

Fig. 7. Mushroom House built against a North-facing Wall.

A mushroom house is a building erected purposely for mushroom culture. It may be wholly or partly above ground, and built of wood, brick, or stone, and extend to any desired dimensions. But a few general principles should be borne in mind. Mushrooms in houses are a winter and not a summer crop, and they are impatient of sudden changes of temperature and of a hot or arid atmosphere. Therefore, build the houses where they will be warm and well-sheltered in winter, so as to get the advantage of the natural warmth, and spare the artificial heat. They should be entered from an adjoining building, or through a porch on the south side, so as to guard against cold draughts or blasts in winter when the door would be opened in going into or coming out of the house. At the same time, do not lose sight of convenience in handling the manure, either in bringing it into the house or taking it out, and with this in view it may be necessary to have a door opening to the outside. All outside doors should be double and securely packed around in winter. Side window ventilators are not necessary, at the same time they are useful in the early part of the season and in summer time; they should be double and tightly packed in winter. The walls, if made of brick, should be hollow, if of wood, double; indeed, walls built as if for an ice house are the very best for a mushroom house, and should be banked with earth, tree leaves, or strawy manure in winter, to help keep the interior of the house a little warmer.

Fig. 8. Section of Mrs. C. J. Osborne's Mushroom House.

The floor should be perfectly dry; that is, so well drained that water will not stand upon it, but it is immaterial whether the floor is an ordinary earthen one or of wood or cement.

Fig. 9. Ground Plan of Mrs. Osborne's Mushroom House.

The roof should be double and always sloping,—never flat. The hoar frost that appears in severe weather inside a single roof is likely to melt as the heat of the day increases, and this cold drip falling upon the beds below is very prejudicial to the mushroom crop. A double roof saves the beds from this drip, and it also renders the house warmer, and less fire is needed to maintain the requisite temperature. One might think that a single roof like that of a dwelling house, and then a flat ceiling under it, would be equivalent to a double sloping roof, but it is not. The moisture arising from the interior of the house condenses upon the flat ceiling, and the water, having no way of running off, drips down upon the beds. With a sloping ceiling or inside roof the water runs down the ceiling to the walls. A very pointed example of this may be seen in Mrs. C. J. Osborne's excellent mushroom house at Mamaroneck, N. Y. It had been built in the most substantial manner, with a sloping roof and a flat ceiling under the roof, but so much annoyance was caused by the drip falling from it upon the beds below that her gardener had the flat ceiling removed and a sloping one built instead, and now it works splendidly, and a few months ago I saw as fine a crop of mushrooms in that house as one could wish to look at.

The interior arrangement of the mushroom house may resemble that of the mushroom cellar. Beds may be made alongside of the walls and, if there is room, also along the middle of the house, and shelves erected in the same way as in the cellar. But in the case of cold, thin outside walls, the shelf-beds should not be built close against them, but instead boxed off about two inches from the walls, so as to remove the beds from the chilling touch of the wall in winter. Economy may suggest the advisability of high mushroom houses, so that one may be able to build one shelf above another, until the shelves are two, three, or four deep. But this is a mistake. The artificial heat required to maintain a temperature of 55° in midwinter in a house built high above ground would be too parching and unsteady for the good of the mushrooms; besides, a second shelf is inconvenient enough, and when it comes to a third or a fourth the inconvenience would be too great, and overreach any advantage hoped for in economy of space. An unheated mushroom house must be regarded as a shed, and treated similarly, as described in the following chapter.

In large, well appointed, private gardens, a mushroom house is considered an almost indispensable adjunct to the glasshouse establishment, and is generally built against the north-facing wall of a greenhouse. In this way it gets the benefit of the warm wall, and may be easily heated by introducing one or two hot-water pipes from the greenhouse system; besides, in winter the house may be entered from the glass house or adjacent shed, and in this way be exempted from the inclement breath of the frosty air that would be admitted in opening the outside door.

Fig. 10. Interior View of Mr. S. Henshaw's Mushroom House.

Mr. Samuel Henshaw's Mushroom House.—Mr. Henshaw has raised mushrooms several years at his place on Staten Island. His mushroom house is nine feet wide and sixty feet long. One side is a brick wall and the other is double boarded. The roof is of tin, in which there are three sashes each two by five feet, supplying ample light. At each end is a door giving convenient access to the interior, for carrying in and removing material without disturbing the bearing beds. In winter the roof is covered with a coating of salt hay, to preserve an equable temperature and prevent the moisture from condensing on the ceiling and falling in drops on the beds. The floor is of earth, which, when well drained, he thinks preferable to either brick or lumber. The floor is entirely covered with beds, no shelves or walks being used. This makes it necessary to step on the beds, but as no covering is employed it is always easy to avoid stepping on the clusters of young mushrooms, and so long as they are left uninjured the bed is seldom, if ever, impaired by the compacting effect of the treading. In order to maintain a necessary winter temperature of 60° a four-inch hot-water pipe extends the whole length of the house about two feet from the floor. On the other side of the brick wall is a greenhouse which, by keeping the wall warm, helps to keep the mushroom house warm. Mr. Henshaw divides this house into three equal beds. The part at the further end of the house is made up in the fall and comes into bearing in December; the middle part a month later to come in a month later, and the near end still a month later, to follow as another succession. Then, if need be, and he wishes to renew the bed at the further end of the house, he clears it out and supplies fresh material for the new bed.

CHAPTER IV.

GROWING MUSHROOMS IN SHEDS.

Any one who has a snug, warm shed, may have a good mushroom house, but it is imperative that the floor should be dry, and the roof water-tight. Of course a close shed, as a tool-house or a carriage-house, is better than an open shed, but even a shed that is open on the south side, if closely walled on the other sides, can also be made of good use for mushroom beds. While open sheds are good enough for beds that yield their crop before Christmas, they are ill-adapted for midwinter beds. The temperature of the interior of a mushroom bed should be about 60° during the bearing period, and the temperature of the surface of the bed 45° to 50° at least; if lower than that the mycelium has a tendency to rest, and the crop stagnates. Now this temperature can not be maintained in an open shed, in hard frosty weather, without more trouble than the crop is worth. The beds would have to be boxed up and mulched very heavily. And even in a close, warm shed, protection in this way would have to be given, but the bed should not be under the penetrating influence of piercing winds and draughts. The mushroom beds should therefore be made in the warmest parts of the warmest sheds.

The beds should be made upon the floor and as much to one side as possible, so as to be out of the way, and in form flat on the ground, or rounded up against the sides of the shed; in the latter case the house should be well banked around on the outside with litter or tree leaves or earth, so as to exclude frost from the lower part of the walls, and thereby prevent the manure in the beds from getting badly chilled. The beds should be made deeper in a cool shed than in a cellar or warm mushroom house, so that they may retain their heat for a long time.

Shelf beds should not be used in unheated sheds, because of the difficulty in keeping them warm in winter. As a rule, shelf beds are not made as deep as are those upon the floor; hence they do not hold their heat so long. When cold weather sets in it is easy to box up and cover over the lower beds to keep them warm, but in the case of shelf beds, that are exposed above and below, it is more trouble to protect them sufficiently against cold than they are worth.

Generally speaking, the term shed is applied to unheated, simple wooden structures; for instance, the wood-shed, the tool-shed, a carriage-house, or a hay-barn. But we often use the name shed to designate heated buildings, as the potting and packing sheds of florists. Were it not that these heated sheds are simply workrooms, and where there is a great deal of going out and in, and, consequently, draughts and sudden and frequent fluctuations of temperature, the treatment of mushroom beds made in them would be the same as that advised for regular mushroom houses; but as the circumstances are somewhat different the treatment, too, should not be the same. A warm potting shed is an excellent place for mushroom beds. Here they should be made under the benches and covered up in front with thick calico, plant-protecting cloth, or light wooden shutters, to exclude cold currents and sudden atmospheric changes, and guard against the beds drying too quickly.

CHAPTER V.

GROWING MUSHROOMS IN GREENHOUSES.

Any one who has a greenhouse can grow mushrooms in it. And it does not matter what kind of greenhouse it is, whether a fruit house, a flower house, or a vegetable house, it is available for mushrooms. One of the advantages of raising mushrooms in a greenhouse is that they grow to perfection in parts of the greenhouse that are nearly worthless for other purposes; for instance, under the stages, where nothing else grows well, although rhubarb and asparagus might be forced there, and a little chicory and dandelion blanched.

Fig. 11. Boxed Mushroom Bed under Greenhouse Bench.

Cool greenhouses, in all cases, are better for mushrooms than hothouses. Cool houses are seldom kept at a lower temperature than 45° or 50° in winter, while hothouses run from 60° to 70° at night, with a rise of ten to twenty degrees by day, and this is too hot for mushrooms. It is a very easy matter, by means of covering with hay or boxing over and covering the boxing with hay or matting, to keep a mushroom bed in a cool house warm and free from marked changes in temperature; but it is a difficult matter to keep a mushroom bed in a hothouse cool enough and prevent sudden rises in temperature.

On Greenhouse Benches.—It sometimes happens that the beds are formed on the greenhouse benches, and the mushrooms occupy the same place that might be assigned to roses or any other planted-out crop. The beds on the benches are made one board deep, that is, eight to ten inches of short, fresh manure, and otherwise as in the case of beds anywhere else. After the beds are spawned and cased with soil, by covering them over with a layer of straw litter or hay, sudden drying out of the surface is prevented, and in order to further prevent this drying it is a good plan to sprinkle some water over the mulching every day or two, but not enough to soak through into the bed. About the time the young mushrooms commence to show themselves, remove the mulching and replace it with a covering of shutters raised another board's height above the bed, or with strong calico or plant-protecting cloth hung curtain-fashion over the beds. The accompanying illustration, Fig. 12, for which I am indebted to Henry A. Dreer, of Philadelphia, gives an excellent idea of how mushrooms may be grown and cared for on greenhouse benches. This illustration, Mr. Dreer writes: "is made from a photograph of a crop grown on the greenhouse benches at the Model Farm, by Mr. McCaffrey, gardener to J. E. Kingsley, Esq., of the Continental Hotel.... No covering of litter is used, but the requisite shading on sunny days is secured by the use of cotton cloth stretched over the top of the bed, as shown in the engraving."

Fig. 12. Mushrooms grown on Greenhouse Benches at Mr. J. E. Kingsley's Model Farm.

My principal objection to mushroom beds on greenhouse benches is their liability to frequent and marked changes of atmospheric temperature and moisture, and to drying out. In midwinter they may be all right, but as spring advances and the sun's brightness and heat increase, the susceptibility of the beds to become dry also increases.

Fig. 13. Wide Bed with Pathway above.

In Frames in the Greenhouses.—Mr. J. G. Gardner has a range of greenhouses some 900 feet long—the longest unbroken string of glasshouses that I know of—for the forcing of fruit and vegetables in winter; grapes, peaches, nectarines, figs, tomatoes, cucumbers, snap beans, peas, lettuce. This range is divided into several compartments, to accommodate the different varieties of crops, also so that some can be run as succession houses. In order to make the most of everything, market-gardener-like, he doubles up his crops wherever possible, and for this end he finds no crop more amenable and profitable than mushrooms. It matters nothing to him whether the house is cold or warm, he can grow mushrooms in it anyway, and in order to be master of the situation he makes his mushroom beds in hotbed frames inside the greenhouses. By attending to ventilating or keeping close, or covering up or leaving bare, he can properly regulate the temperature of the mushroom bed, no matter how hot or cold the atmosphere of the greenhouse may be. In the same way—by shading the panes or unshading them—he governs the light admitted to the mushrooms.

The greenhouses in which the mushrooms are grown are orchard houses, that is, glasshouses in which peach and nectarine trees are grown and forced. As these trees fruit and finish their growth early, it is necessary that they be kept as cool and inactive as possible in the fall and early winter, and started again into growth in late winter. In the fall, therefore, the fermenting material being confined in frames retains warmth enough for the proper development of the mushrooms, and as the winter advances and the heat in the frames begins to wane it becomes necessary to begin heating the greenhouses in order to start the trees into bloom and growth, and thus are provided very favorable conditions for the continued production of the mushroom crop.

Fig. 14. Mushrooms on Greenhouse Benches under Tomatoes.

The frames used are common hotbed box frames seven feet wide and carrying three and one-half feet wide sashes. A string of them is run along the middle of the greenhouses, for greenhouse after greenhouse is occupied by them. They are flat upon the floor, and in the early part of the season alone in the greenhouses. But as the winter advances a temporary staging is erected over these frames, on which spiræas, peas, beans, or other flowers or vegetables are to be grown. These love the light and a position near the glass, whereas the mushrooms grow perfectly well in the dark quarters of the frames under the stages. If he did not grow mushrooms under these stages the room would be unoccupied, hence unproductive; but by occupying it with mushrooms he not only gets peaches and snap beans at once out of the same greenhouse, but also a crop of mushrooms, often worth as much as the other two.

In preparing the beds in the frames they were made up a foot deep, very firm, and with New York stable manure brought direct from the cars. There was no preliminary preparation of the manure. A layer of loam one and one-half inches deep was then spread over the surface and forked into the bed of manure one and one-half inches deep, so as to form an earthy mat three inches deep. This was then packed solid with the feet, and a two-inch layer of loose manure added all over. In about ten days the temperature three inches below the surface was about 95°, and the beds were then spawned. In spawning, drills were drawn across the beds about a foot apart and just deep enough to touch but not penetrate the earthy mat before referred to. The broken spawn was then sown in the drills and covered with a layer of loam one and one-half to two inches deep, which was tamped slightly. The sashes were then put on and tilted up a little to let the moisture escape. By the time the mushrooms appeared there was very little need of ventilating, as the condensation of moisture on the glass was scarcely apparent; but ventilation is easily guided by the appearance of moisture on the glass, the more of this the more ventilation should be given. To begin with, there was no attempt at shading the frames; but as soon as the mushrooms began to appear the beds were shaded, and mostly by the crops of other plants on the stages above them. These frame beds were made up last October, and began bearing in December, and on March 14 Mr. Gardner wrote me: "The mushrooms in my frames have done grandly. I cut large basketfuls to-day of the finest mushrooms I have ever seen, some of them measuring five inches in diameter before being fully expanded."

And further, in submitting the above notes to him for verification, he adds: "There is one vital point we should impress upon all who grow mushrooms in frames or under greenhouse benches, namely, that sudden changes of temperature must be avoided. While light, in my opinion, is good for mushrooms, it causes a rise of temperature, and this we must guard against. In order to maintain a uniform temperature all glass exposed to light or heat in any other way should be covered with some non-conducting material. Rye straw is the best thing for this purpose that I know of. Indeed, neglect of this simple matter, in cases where sunlight and heat from hot-water pipes come in contact with the young mushrooms or mycelium on the surface of the beds, is the cause of many failures in growing in frames and greenhouses."

Under Greenhouse Benches.—Open empty spaces under the stages anywhere are good places for mushroom beds. However, carefully observe a few points, to wit: A dry floor under the beds is imperative, for a wet floor soaks and chills the beds, and renders them unhealthy for the spawn; but the common earth floor is good enough, provided water does not stand upon it at any time; if it does, the floor to be under the beds can be rendered dry by raising it a little higher than the general level, or using a flooring of old boards. Beds should not be built close up against hot-water pipes, steam pipes, or smoke flues, as the heat from these when they are in working condition will bake the parts of the beds next to them and render them unproductive, and also crack and spoil the caps of the mushrooms that come up within a foot or two of the pipes. But this injury from hot pipes and flues can be lessened greatly by boxing the pipes, so as to shut off the heat from the mushroom beds and allowing it full escape upward; then the beds can be made, with safety, up to within a foot of the pipes. As a rule, hot-water pipes are run around under the front benches of a greenhouse, then it would not be advisable to make beds under those benches. The middle bench is the one most commonly free from pipes, hence the one best adapted for beds. It has more headroom, and therefore easier working facilities. Steam-heated greenhouses generally present the best accommodations for mushroom beds, because the pipes occupy less room under the benches than do those for hot water, and they are always kept higher from the ground.

Among Other Plants on Greenhouse Benches.—It sometimes happens that mushrooms spring up spontaneously among the roses, carnations, violets, mignonette, and other crops that are grown "planted out" on the benches, and this is particularly the case where fresh soil had just been used, in whole or part, for filling the bench beds. These mushrooms come from natural spawn contained in the loam or manure before they were brought indoors, and which is apt to be true virgin spawn. The mushrooms are generally of the common kind, grown from brick spawn, but occasionally a much larger and heavier sort is produced, and this is the "horse" mushroom. It is perfectly good to eat, only of coarser quality than the other.

A fair and certain crop can be obtained by planting pieces of spawn in the beds here and there between the plants and where they will be least likely to be soaked with water. In order to further insure the development of the spawn, holes about the size of a pint cup should be scooped out here and there over the bed, and filled up solidly with quite fresh but dry horse droppings, with the piece of spawn in the middle, and covered over on top with an inch of loam, so as to leave the whole surface of the bed level. So small a quantity of dry manure surrounded with cold earth will not heat perceptibly, and the moisture of the loam about it will soon moisten it, no matter how dry it may be. The dry, fresh droppings are the very best material for starting the mycelium into growth.

Growing Mushrooms in Rose Houses.—George Savage, the head gardener at Mr. Kimball's greenhouses, Rochester, N. Y., grows mushrooms very successfully under the benches of the rose houses. When he makes up his earliest mushroom beds in the fall the rose house is kept cool, and this is an advantage to the mushroom beds, which get all the warmth they need from the fermenting manure; but as November advances, and the heat in the beds begins to wane the rose houses are "started," and this artificial warmth comes in good season to benefit the growing mushrooms. The roses, in this case, are planted out on benches, hence there is scarcely any dripping of water from above upon the mushroom beds below.

Mr. George Grant, of Mamaroneck, N. Y., who grows mushrooms in the greenhouse, I called to see last January, and was very much pleased with his simple and successful method. The beds were then in fine bearing, very full, and the crop was of the best quality. The beds were made upon the earthen floor of his tomato-forcing house and under the back bench. The bed was flat, seven to eight inches deep, with a casing of a ten-inch-wide hemlock board set on edge at the back, and another of same size against the front. The bed was made of horse droppings, six inches deep, and molded over with fresh loam one and one-half inch deep. Over the whole, and resting on the edges of the hemlock boards, was a light covering of other boards, with a sprinkling of hay on top of them to arrest and shed drip, and maintain an equable temperature in the bed.

Mr. Abram Van Siclen, of Jamaica, Long Island, is one of the largest mushroom growers for market in the country, as well as one of the most extensive growers of market-garden truck under glass around New York. He devotes an immense area under his lettuce-house benches to the cultivation of mushrooms. The beds are made upon the floor in the usual way, only for convenience' sake, to admit of plenty of room in making up the beds and gathering the crop, besides avoiding the necessity for building higher structures than the ordinary lettuce greenhouses, the mushroom beds are sunken about eighteen to twenty-four inches under the level of the pathways. As the lettuces are planted out upon the benches there is very little drip from them, hence the sunken beds are well enough. And the temperature of a lettuce house is about right for a long-lasting mushroom bed. Light is excluded by a simple covering of salt hay laid over the beds, and sometimes by light wooden shutters set up against the aperture between the lettuce benches and the floor, in this way boxing in the mushrooms in total darkness.

Mr. William Wilson, of Astoria, has an immense greenhouse establishment near New York. In his greenhouses, under both the side and middle benches, he grows mushrooms, and when I saw them in January there were about 300 square yards of beds. The beds were flat, about nine inches thick, built upon the ground, and protected from strong light by having muslin tacked over the openings between the benches and the beds alongside the pathways. But his crop was suffering from drip. Mr. Wilson told me he could not begin to supply the demand. He says whatever he makes on mushrooms is mostly clear gain. They occupy space that otherwise would remain unoccupied, and he needs the manure and the loam in his florist business, and it is in better condition for potting after it has been rotted in the mushroom beds than it was before it was used for this purpose.

Fig. 15. Mr. Wm. Wilson's Mushroom Beds.

Drip from the Benches.—This must be prevented from the beds above, else it will soak or chill, and in a large measure kill the spawn. I have seen many examples of this evil. The beds would be full of drip holes all over their surface, and although a good many mushrooms here and there about the bed might perfect themselves, multitudes only reach the pin-head condition—or possibly the size of peas—and then fogg off in patches. It is not one or two little mushrooms in a clump that fogg off, but where one foggs off all of the little ones in that patch go, for it is not a disease of the individual mushroom, but of the mycelium or mushroom plant that runs in the bed, and when this is injured or killed all the little mushrooms arising from this particular patch of plant are robbed of sustenance and must perish.

In greenhouses where the benches are occupied with roses, carnations, bouvardias, violets, or lettuces, "planted out," as commercial florists and gardeners generally grow them, there is very little drip, because while the plants on these benches are freely watered, the soil is never soaked enough for the water to drain from it in dripping streamlets, as is continually the case in greenhouses where potted plants are grown on the stages. Under these "planted out" benches, if care is exercised, mushrooms can be grown in open beds; in fact, it is about the best place and condition for them in a greenhouse.

Fig. 16. Mushroom Bed built flat upon the Ground.

With stages occupied by plants in pots provision needs to be made to ward off the drip from the mushroom beds, by erecting over, and conveniently high above them, a light wooden framework, on which rest light wooden frames covered with oiled paper, oiled muslin, or plant-protecting cloth. In fact, three light wooden strips run over the bed, as shown in [Fig. 12], or three strings of stout cord or wire run in the same manner will answer for small beds, and act as a support for the oiled muslin or plant-protecting cloth. Building paper is sometimes used for the same purpose. Mr. J. G. Gardner uses ordinary hotbed frames and sashes, as described in a previous chapter. Light wooden shutters—made of one-half inch or five-eighths inch pine—may be used for the same end, and will last for many years.

Fig. 17. Ridged Mushroom Bed.

The beds under the greenhouse benches may be made up in the same way as are beds anywhere else; that is, flat upon the floor and between two boards set on edge, as seen in Fig. 16, or in ridges under the high or middle benches, as in Fig. 17, or in banked beds against the back wall, as shown in Fig. 18. Generally the flat bed is the most convenient to make and take care of.

Fig. 18. Banked Bed against a Wall.

In open, airy greenhouses it is always well to inclose the mushroom beds in box casings and with sash or shutter coverings, to prevent draughts and fluctuations of temperature and atmospheric moisture. This can easily be done by making the sides a board and a half (fifteen inches), or two boards (twenty inches) high, and covering over with light wooden shutters, sashes, or muslin or paper-covered light frames. See [Fig. 11.]

Ammonia Arising.—Ammonia arising from the manure of the mushroom beds in the greenhouse may be injurious to the other inmates of the greenhouse. If the manure has been well prepared before it was introduced into the greenhouse, the ammonia arising from it will not, in the least degree, injure any other plants or flowers that may be in the house; but if the manure is fresh, hot, and rank, the opposite will be the case. Beds in greenhouses should always be made up of manure that has been well prepared beforehand out of doors or in a shed, and as it is brought into the greenhouse it should at once be built solidly into the beds. Then very little steam will arise from the beds; in fact, it will be imperceptible to sight or smell.

CHAPTER VI.

GROWING MUSHROOMS IN THE FIELDS.

Under suitable conditions we can grow mushrooms easily and abundantly in the open fields, and the planting of the spawn is all the trouble they will cause us. During the late summer and fall months mushrooms often appear spontaneously and in great quantity in our open pastures, but in their natural condition they are an uncertain crop, as in one year they may occur in the greatest abundance, and in the next perhaps none can be found in the fields in which they had been so numerous the previous year. Why this should be so is not very clear. The popular opinion is that after a dry summer mushrooms abound in the fields, but after a wet summer they are a very scarce crop; and the inference is that the moisture has killed the spawn in the ground. This may be true to a certain extent, but how does it happen—as it certainly often does—that good spawn planted by hand in the fields in early summer will produce mushrooms toward fall no matter whether the summer has been wet or dry? At the same time, it is true that a wet spell immediately succeeding the planting of the spawn will kill a great deal of it.

As a rule, wild mushrooms abound most in rich, old, well-drained, rolling pasture lands, and avoid dry, sandy, or wet places, or the neighborhood of trees and bushes. In attempting to cultivate them in the open fields we should endeavor to provide similar conditions. Then the chief requisite is good spawn, for without this we can not raise mushrooms.

About the middle of June take a sharp spade in the pasture, make V or T-shaped cuts in the grass sod about four inches deep and raise one side enough to allow the insertion of a bit of spawn two to three inches square under it, so that it shall be about two inches below the surface, then tamp the sod down. By cutting and raising the sod in this way, without breaking it off, it is not as likely to die of drought in summer. In this way plant as much or little as may be desired and at distances of three, four, or more feet apart. During the following August or September the mushrooms should show themselves, and continue in bearing for several weeks.

Mr. Henshaw, of Staten Island, who has been very successful in growing mushrooms in the fields as well as indoors, writes to me as follows: "You ask me to give you my plan of growing mushrooms in the fields during the summer. It is very simple. About the end of June, or as soon as dry weather sets in, we remove the old beds from our mushroom house, and if there should be any live spawn in the bottom of our beds we put it in a wheelbarrow and take it to the field, where we plant it in the open places, but never under trees. In planting, we lift a sod and put a shovelful of the manure containing the spawn in the hole, then replace the sod and beat it down firm; this we do at distances of twelve feet apart. If we have no live spawn from our indoor beds we take the common brick spawn, and put about a quarter of a brick into each hole, returning and beating down the sod as already stated. This is all that is done. If there comes a dry time after the spawn is put in the pasture we are sure to have a good supply of mushrooms in the fall."

A few years ago Carter & Co., seedsmen, London, sent this to one of the gardening periodicals: "The following mode of growing mushrooms in meadows by one of our customers may be interesting to your readers: In March (May would be soon enough here) he begins to collect droppings from the stables. These, when enough have been gathered together, are taken into the meadow, where holes dug here and there about one foot or eighteen inches square are filled with them, the soil removed being scattered over the surrounding grass. When all the holes have been filled and made solid he then places two or three pieces of spawn about one inch square in each hole, treads all down firmly, replaces the turf and beats it tightly down. Under this system, in August and September mushrooms appear without fail in abundance and without any further care. The method is simple and the result certain. Therefore all who happen to have a meadow, paddock, or grass field, and are fond of mushrooms, should try the experiment.... In the case in question fresh holes were spawned every year."

CHAPTER VII.

MANURE FOR MUSHROOM BEDS.

In order to grow mushrooms successfully and profitably a supply of fresh horse manure is needed, and this should be the very best that is made, either at home or bought from other stables. The questions of manure and spawn are the most important that we have to deal with. Very few make their own spawn, as it is bought and accepted upon its good looks,—often rather deceptive,—but the manure business is entirely in our own hands, and success with it depends absolutely upon ourselves. We can not reasonably expect good results from poor manure nor from ill-prepared manure. It is only from the very best of horse manure prepared in the very best fashion that we can hope for the very best crops of the best mushrooms.

Horse Manure.—There are various kinds of horse manure, differing materially in their worth for mushroom beds. The kind of manure depends upon the condition of the horses, how they are housed, fed, and bedded, and how the manure is taken care of. But while the manure of all healthy animals is useful for our purpose, there still is a great choice in horse manure. If we are dependent upon our home supply we may use and make the best of what we have, but if we have to buy the manure we should be very particular to select the best kind of manure and accept of no other.

The very best manure is that from strong, healthy, hard-worked, well-kept animals that are liberally fed with hard food, as timothy hay and grain, and bedded with straw. And if the bedding be pretty well wetted with urine and trampled under the horses' feet, so much the better; indeed, this is one reason why manure from farm and teamsters' stables is better than that from stylish establishments, where everything is kept so scrupulously dry and clean.

Fig. 19. Perspective View of the Dosoris Mushroom Cellar.

The fresher the manure is the better, still manure that is not perfectly fresh may also be quite good. Stable manure may accumulate in a cellar for a couple of months, and still be first rate. After our hotbed season is over I stack our stable manure high in the yard, and from June until August, as the manure is taken away from the stable each day, it is piled on the top of this stack. My object is to keep it so dry that it can neither heat nor rot. In August the stack is broken down and the best manure shaken out to one side for mushrooms, and the long straw and rotted parts thrown to the other side. This short manure, when moistened with water and thrown into a heap, exposed to the sun for a day or two, will heat up briskly. The beds illustrated in Fig. 19 were made from manure prepared in this way in August.

In the case of quite fresh manure, let it accumulate for a few days, or a fortnight, even, until there is enough of it to make up a bed, and then prepare it. Be very particular to prevent, from the first, its heating violently or "burning" while accumulating in the pile. Beds made from very fresh manure respond quickly and generously. The crop comes in heavily to begin with, and continues bearing largely while it lasts, but its duration is usually shorter than in the case of a bed made up of less fresh manure. But altogether it yields a better and heavier crop than a bed that comes in more gradually and lasts longer, and the mushrooms are of the finest quality.

Some growers use the droppings only, and reject all of the strawy part, or as much of it as they can conveniently shake out. This gives them an excellent manure and perhaps the very best for use on a small scale or in small beds. When mushrooms are to be grown in boxes, narrow troughs, half barrels, and other confined quarters, it is well to concentrate the manure as much as possible—use all the droppings and as little straw as you can. But droppings alone for large beds would take too much manure and cost too much, and they would not be any better than with a rougher manure.

Always preserve the wet, strawy part of the manure, along with the droppings, and mix and ferment them together, and in this way not only add largely to the bulk of the pile, but secure the benefits afforded by the urine without reducing, in any way, the strength or fermenting properties of the manure. Shake out all the rank, dry, strawy part of the manure and lay it aside for other purposes. This may be of further use as bedding in the stables, covering the mushroom beds after they have been made up, or for hotbeds; if well wetted with stable drainings, or even plain water, it forms a ready heating material.

Many a time when we have been short of home-made manure I have bought some loads here and there from different stables in the village, and mixed all together and made it into beds with excellent results. Sometimes when the manure under preparation had been rather old and cool, I have added a fifth or tenth part of fresh droppings to it, with very quickening effect in heating and apparent benefit to the crop.

It is generally believed that the manure of entire horses is better for mushrooms than that of other horses, but positive evidence in this direction has never come under my observation. Some practical men assert that there is no difference. Mr. John G. Gardner, at the Rancocas Farm, who has had abundant opportunity to test this matter, tells me that he has given it a fair trial and been unable to find any difference in the quality or quantity of mushrooms raised from beds made from the manure of entire horses and those raised from beds made from the manure of other equally as well fed animals. But the Parisian growers insist that there is a difference in favor of entire horses, especially in the case of hard-worked animals such as are engaged in heavy carting.

Manure of horses that are largely fed with carrots is emphatically condemned by most writers on the cultivation of mushrooms; indeed, it is one of the points in every book on mushrooms which I have read. Let us look at a few practical facts: There are at Dosoris two shelf beds in one cellar; each is thirty feet long, three feet wide, and nine inches deep, and both are bearing a very thick crop of mushrooms. The material in these beds consists of horse manure three parts and chopped sod loam one part, which had been mixed and fermented together from the first preparation. The manure was saved from the stables on the place in November, '88, the materials prepared in December, the beds built Dec. 17, spawned Dec. 24, molded over Dec. 31, and first mushrooms gathered Feb. 7, 1889. These beds bore well until the middle of April. The mushrooms did not average as large as they did on the deeper beds upon the floor of the cellar, but they ran about three-fourths to one ounce apiece, and a good many were more than this. It is most always the case, however, that the crop on thin shelf beds averages less than it does on thick floor beds, and especially is this noticeable after the first flush of the crop has been gathered, no matter what kind of fermenting material had been used. At the time when the manure used for these beds was being saved at the stable the horses were only very lightly worked, and to each horse was fed, in addition to hay and some oats and bran, about a third of a bushel of carrots a day. And this is the manure used for the late mushroom beds, and yet good crops and good mushrooms are produced. This is not only the experience of one year's practice but the regular routine of many.

Perhaps some one would like to ask: Do you consider the manure of carrot-fed horses as good as the manure of animals to which no carrots or other root crops had been fed? My answer is—decidedly not. While the manure of carrot-fed animals is not the best, at the same time it is good, and any one having plenty of it can also have plenty of mushrooms. The complete denunciation of the manure of carrot-fed horses so emphatically stereotyped upon the minds and pens of horticultural writers is not always founded on fact.

Manure of Mules.—This is regarded as being next in value to that of entire horses, and some French growers go so far as to say that it is quite as good. Mr. John G. Gardner tells me of an extraordinary crop of mushrooms he once had which astonished that veteran, Samuel Henshaw, and that it was from beds made of manure from mule stables. Certainly the heaviest crop of mushrooms I ever did see was at Mr. Wilbur's place at South Bethlehem, Pa., four years ago, and the beds were of clean mule droppings from the coal mines. Mule manure can be had in quantity at our mule stock yards, which are in nearly every large city in the Middle and Southern States. Getting it from the mines costs more than it is worth, except as a fancy article; the men will not collect and save it for any reasonable price.

Cellar Manure.—Many stables have cellars under them into which the manure and urine are dropped at every day's cleaning. These cellars are not generally cleaned out before a good deal of manure has accumulated in them, say a few weeks', or a few months', or a winter's gathering, and it is commonly pretty well moistened by the urine. If this manure has not become too dry and "fire-fanged" in the cellar it is splendid for mushrooms. We buy a good deal of it, but are particular to reject the very dry and white-burned parts. Sometimes the manure from the cow-stables, as well as from the horse-stables, is dropped together into the cellar; then I would give less for the manure, especially if the cow manure predominated, because in the working it keeps too cold and wet and pasty; but if there is not cow manure enough to give the mass a pasty character it will make capital mushroom beds. Pigs often have the run of the manure-cellar, as is generally the case in farmyards. I would not use any part of this mixed pig manure. Mycelium evades hog manure; besides it is impure and malodorous, and a propagating bed for noxious insect vermin. It matters very little what kind of bedding is used, in the case of cellar manure, but I would not buy it if sawdust or salt hay had been used as bedding. Neither of these materials, in limited quantity, is deleterious to the mushrooms; at the same time, they are far less desirable than straw, field hay, German peat moss, or corn stalks, and there are risks enough in mushroom-growing without courting any that we can as well avoid.

City Stable Manure.—Around New York this can always be had in any quantity at a reasonable rate, and it is first-rate manure for mushroom beds. Market gardeners haul in a load of vegetables to market and bring back a load of manure; others may buy and haul home manure in the same way, or make arrangements with a teamster to do it for them. But the whole matter of city manure is now so deftly handled by agents, who make a special business of it, that we can get any quantity of manure, from a 500 lb bale to an unlimited number of loads, and of most any quality, delivered near or far, inland or coastwise, at a fairly moderate price. It is the city stable manure that nearly all our large market growers use for their mushroom beds. When they get it at the stables and cart it home themselves they know what they are handling, and should take only fresh horse dung. In ordering it of an agent be particular to arrange for the freshest and cleanest, pure horse manure. They will get it for you. We get several hundreds of loads of this selected manure from them every year for hotbeds, and find it excellent. We also get 1000 to 2000 loads of the common New York stable manure a year for our general outdoor crops, and it also is capital manure in its way, but not so good as the selected manure for mushrooms. It is mixed a little and smells very rank, and in mushroom beds usually produces a good deal of spurious fungi. Most all of our largest mushroom growers, Van Siclen of Jamaica, Denton of Woodhaven, Connard of Hoboken, and others, live within easy hauling distance of the city, and are able to select and get the very choicest manure at a very cheap rate.

Baled Manure.—Within a year or two a good deal of our city horse manure has been put up in bales and thus shipped and sold. Each bale contains from 350 to nearly 500 lbs, and is made up, pressed and tied in about the same way as baled hay. The principal advantages of the bales are these: Only the cleanest horse manure is put up in this way; cow manure, offal, spent hops, or other short or soft manures are not included in the bales, nor, on account of shipping considerations, are malodorous manures of any sort permitted in them. The railroads allow baled manure to be put off on their platforms, and closer to their stations than they would allow loose manure; and it often happens that an agent will send a carload to a railroad station and dump it off there so that the people around who have only small garden lots can have an opportunity of buying one or more bales, just as they need it, and without, as is generally the case, having to buy a whole load when they need only half a load. These bales are quite a boon to people who would like to have a small bed of mushrooms in their cellar and who have no other manure. Bring home one or more bales, open them, spread out the manure a little, and when it heats turn it a few times, and it will soon be ready for use. Or if you do not wish to litter up the place, roll the bales into the cellar, shed, or wherever else you wish to make use of them, and mix about one-fourth of their bulk of loam with the manure and make up the bed at once.

The Board of Health of New York city is very emphatic in its endeavors to rid the city of any accumulation of manure and, a year ago, had under consideration a plan to compel the manure agents, for sanitary reasons, to bale the stable manure. And perhaps this is the reason why it is so easily procured, to wit: A New York gentleman, desirous of engaging in the mushroom-growing business, writes me: "I get my manure from the city in bales. All it costs me is the freight to my place at White Plains." Lucky gentleman! With any amount of the best kind of stable manure gratis, no wonder he wishes to embark in the mushroom ship.

Cow Manure.—This is sometimes used with horse manure in forming the materials for a mushroom bed, and several European writers are emphatic in advocating its use. But I have tried it time and time again, and in various ways, and am satisfied that it has no advantage whatever over plain horse manure, if, indeed, it is as good. It is not used by the market growers in this country.

The best kind of cow manure is said to be the dry chips gathered from the open pastures; these are brought home, chopped up fine and mixed with horse manure. The time and expense incurred in collecting and chopping these "chips" completely overreach any advantages that might be derived from them, no matter how desirable they may be. The next best kind of cow manure is that of stall-fed cattle, to which dry food only, as hay and grain, is fed. This is seldom obtainable except in winter, and is then available for spring beds only. This I have used freely. One-third of it to two-thirds of dry horse manure works up very well, heats moderately, retains its warmth a long time, also its moisture without any tendency to pastiness; the mycelium travels through it beautifully, and it bears fine mushrooms. Still, it is no better than plain horse manure. The poorest kind of cow manure is the fresh manure of cattle fed with green grass, ensilage, and root crops; indeed, such manure can not be used alone; it needs to be freely mixed with some absorbent, as dry loam, German moss, dry horse droppings, and the like, and even then I have utterly failed to perceive its advantages; it is a dirty mass to work, and quite cold.

In the manufacture of spawn, however, cow manure is a requisite ingredient, and here again the manure of dry fed animals is better than that of those fed with green and other soft food. But my chief objection to the use of cow manure in the mushroom beds is that it is a favorite breeding and feeding place for hosts of pernicious bugs and grubs and earth worms,—creatures that we had better repel from, rather than encourage in, our mushroom beds.

German Peat Moss Stable Manure for Mushroom Beds.—Although I have not yet had an opportunity of trying this material for mushroom beds, Mr. Gardner, of Jobstown, has great faith in it; so, too, has that prince of English mushroom growers, Richard Gilbert, of Burghley, who relates his success with it in growing mushrooms in the English garden papers. This peat moss is a comparatively new thing in this country, and is used in place of straw for bedding horses. It is a great absorbent and soaks up much of the urine that, were straw used instead, would be likely to pass off into the drains. To this is ascribed its great virtue in mushroom culture. It should be mixed with loam when used for mushroom beds.

Fig. 20. Bale of German Peat Moss.

Sawdust Stable Manure for Mushroom Beds.—This is the manure obtained from stables where sawdust has been used for bedding for the horses. It is a good absorbent and retains considerable of the stable wettings. Such manure ferments well, makes up nicely into beds, the mycelium runs well in it, and good mushrooms are produced from it. But if I could get any other fairly good manure I wouldn't use it. I remember seeing it at Mr. Henshaw's place some years ago. He had bought a quantity of fresh stable manure from the Brighton coal yards, where sawdust had been used for bedding for the horses, and this he used for his mushroom beds. I went back again in a few months to see the bed in bearing, but it was not a success. At the same time, some European growers record great success with sawdust stable manure. George Bolas, Hopton, Wirkeworth, England, sent specimens of mushrooms that he grew on sawdust manure beds to the editor of the Garden, who pronounced them "in every way excellent." Mr. Bolas says: "In making up the bed I mixed about one-third of burnt earth with the sawdust, sand, and droppings. The mushrooms were longer in coming up than usual, the bed being in a close shed, without any heat whatever. They have, however, far exceeded my expectations."

Richard Gilbert, of Burghley, also wrote to the Garden, April 25, 1885: "There is nothing new in growing mushrooms in sawdust. I have done it here for years past; that is to say, after it had done service as a bed for horses, and got intermixed with their droppings. I have never been able to detect the least difference in size or quality between mushrooms grown in sawdust and those produced in the ordinary way."

Tree Leaves.—Forest tree leaves are often used for mushroom beds, sometimes alone, instead of manure, but more frequently mixed with horse manure to increase the bulk of the fermenting material. Oak tree leaves are the best; quick-rotting leaves, like those of the chestnut, maple, or linden, are not so good, and those of coniferous trees are of no use whatever. As the leaves must be in a condition to heat readily they should be fresh; such are easily secured before winter sets in, but in spring, after lying out under the winter's snow and rain, their "vitality" is mostly gone. But we can secure a large lot of dry leaves in the fall and pile them where they will keep dry until required for use. As needed we can prepare a part of this pile by wetting the leaves, taking them under cover to a warm south-facing shed, and otherwise assisting fermentation just as if we were preparing for a hotbed. While moistening the leaves with clean water will induce a good fermentation, wetting them with liquid from the horse-stable urine tanks will cause a brisk heat, and for mushrooms produce more genial conditions.

Mushroom beds composed in whole or part of fermenting tree leaves should be much deeper than would be necessary were horse manure alone used; for half leaves and half manure, say fifteen inches deep; for all leaves, say twenty to thirty inches deep.

While mushroom spawn will run freely in leaf beds and we can get good mushrooms from them, my experience has satisfied me that we do not get as fine crops from these beds or any modification of them as from the ordinary stable manure beds. And we can not wonder much at this, considering that the wild mushroom is scarcely ever found in the neighborhood of trees or where leaf mold deposits occur.

Spent Hops.—We can make good use of this in one way. If we are short of good materials for a mushroom bed, we can first make up the beds eight or ten inches deep with fermenting spent hops, and above this lay a four or five inch layer of horse manure, or this and loam mixed. The hops will keep up the warmth, and the manure affords a congenial home for the mushroom spawn. But we should never use spent hops alone, nor so near the surface of the beds that the spawn will have to travel through it.

Spent hops can be had for nothing, and our city brewers even pay a premium to the manure agents to take the hops away.

CHAPTER VIII.

PREPARATION OF THE MANURE.

Get as good a quality of fresh horse manure as you can, and in sufficient quantity for the amount of bed or beds you wish to make. Next get it into suitable condition for making up into beds. This can be done out of doors or under cover of a shed, but preferably in the shed. Out of doors the manure is under the drying influence of sun and wind, and it is also liable to become over-wetted by rain, but under cover we have full control of its condition. All the manure for beds between July and the end of October is prepared out of doors on a dry piece of ground, but what is used after the first of November, all through the winter, is handled in a shed open to the south. During the autumn months we get along very well with it out of doors; after every turning cover the heap with strawy litter to save it from the drying influences of sun and wind. Remove this covering when next turned, and lay light wooden shutters on top of it as a precaution against rain. In the shed in winter the manure is protected against rain and snow and we can always work it conveniently; when the shed is open to the south—as wagon and wood-sheds often are—we get the benefit of the warm sunshine in the daytime in starting fermentation in the manure, but in the event of dull, cold weather, cover up the pile quite snugly with straw and shutters to start the heat in it. Altogether, a warm, close shed would be better.

It seldom happens that one can get all the manure he wants at one time; it accumulates by degrees. This is the case with the market grower who uses many tons, and hauls it home from the city stables a little at a time; also with the private grower, who uses only a few bushels or half a cord, and has it accumulate for days or weeks from his own stable. As the manure accumulates throw it into a pile, straw and all, but not into such a big pile that it will heat violently; and particularly observe that it shall not "fire-fang" or "burn" in the heap. If it shows any tendency to do this, turn it over loosely, sprinkle it freely with water, spread it out a little, and after a few hours, or when it has cooled off nicely, throw it up into a pile again and tread it firmly to keep it moist and from heating hastily.

When enough manure has accumulated for a bed, prepare it in the following way: Turn it over, shaking it up loosely and mixing it all well together. Throw aside the dry, strawy part, also any white "burnt" manure that may be in it, and all extraneous matter, as sticks, stones, old tins, bones, leather straps, rags, scraps of iron, or such other trash as we usually find in manure heaps, but do not throw out any of the wet straw; indeed, we should aim to retain all the straw that has been well wetted in the stable. If the manure is too dry do not hesitate to sprinkle it freely with water, and it will take a good deal of water to well moisten a heap of dry manure. Then throw it into a compact oblong pile about three or four feet high, and tread it down a little. This is to prevent hasty and violent heating and "burning," for firmly packed manure does not heat up so readily or whiten so quickly as does a pile loosely thrown together. Leave it undisturbed until fermentation has started briskly, which in early fall may be in two or three days, or in winter in six to ten days, then turn it over again, shaking it up thoroughly and loosely and keeping what was outside before inside now, and what was inside before toward the outside now; and if there are any unduly dry parts moisten them as you go along. Trim up the heap into the same shape as you had before, and again tread it down firmly. This compacting of the pile at every turning reduces the number of required turnings. When hot manure is turned and thrown loosely into a pile it regains its great heat so rapidly that it will need turning again within twenty-four hours, in order to save it from burning, and all practical men know that at every turning ammonia is wasted,—the most potent food of the mushroom. We should therefore endeavor to get along with as few turnings as possible; at the same time, never allow any part of the manure to burn, even if we have to turn the heap every day. These turnings should be continued until the manure has lost its tendency to heat violently, and its hot, rank smell is gone,—usually in about three weeks' time. If the manure, or any part of it, is too dry at any turning, the dry part should be sprinkled with water and kept in the middle of the heap. Plain water is what is generally used for moistening the manure, but I sometimes use liquid from the stable tanks, which not only answers the purpose of wetting the dry materials, but it also is a powerful stimulant and welcome addition to the manure. But the greatest vigilance should be observed to guard against overmoistening the manure; far better fail on the side of dryness than on that of wetness.

If the manure is too wet to begin with it should be spread out thinly and loosely and exposed to sun and wind, if practicable, to dry. Drying by exposure in this way is not as enervating as "burning" in a hot pile, and better have recourse to any method of drying the manure than use it wet. If, on account of the weather or lack of convenience for drying, the manure can not be dried enough, add dry loam, dry sand, dry half-rotted leaves, dry peat moss, dry chaff, or dry finely cut hay or straw, and mix together.

The proper condition of the manure, as regards dryness or moistness, can readily be known by handling it. Take a handful of the manure and squeeze it tight; it should be unctuous enough to hold together in a lump, and so dry that you can not squeeze a drop of water out of it.

Some private gardeners in England lay particular stress upon collecting the fresh droppings at the stables every day, and spreading them out upon a shed or barn floor to dry, and in this way keeping them dry and from heating until enough has accumulated for a bed, when the bed is made up entirely of this material, or of part of this and part of loam. But market gardeners, the ones whose bread and butter depend upon the crops they raise, never practice this method, and that patriarch in the business, Richard Gilbert, denounces the practice unstintedly.

Different growers have different ideas of preparing manure for mushroom beds, but the aim of all is to get it into the best possible condition with the least labor and expense, and to guard against depriving it of any more ammonia than can be helped. See Mr. Gardner's method of preparing manure, [p. 22.]

Loam and Manure Mixed.—Mushroom beds are often formed of loam and manure mixed together, say one-third or one-fourth part of the whole being loam, and the other two-thirds or three-fourths manure; if a larger proportion of loam is used it will render the beds rather cold unless they are made unusually deep. I am not prepared to affirm or deny that this mixed material has any advantages over plain manure; I use it considerably every year and with good results; at the same time, I get as good crops from the plain manure beds. But it has many warm friends who are excellent growers.

In preparing this mixed material I use fresh sod loam well chopped up, and add it to the manure in this way: First select the manure and throw it into a heap to ferment, as before explained; then after the first turning cover the heap with a layer of this loam about three or four inches thick, enough to arrest the steam; at the next turning mix this casing of loam with the manure, and when the heap is squared off add another coating of loam of the same thickness in the same way as before, and so on at each turning until the whole mass is fit for use, and the full complement of loam, say one-fourth the full bulk, has been added. In this way much of the ammonia that otherwise would be evaporated from the manure is arrested and retained.

Some growers, when they first shake out their fresh manure, add the full complement of loam to it at once and mix them together. Others, again, Mr. Denton, of Woodhaven, for instance, prepare the manure in the ordinary way and when ready for use add the quota of loam. I use good sod loam for two reasons, namely, because it is the very best that can be used for the purpose, and, also, after being used in the mushroom beds it is a capital material, and in fine condition for use in potting soft-wooded plants. But the loam commonly used to mix with the manure is ordinary field soil. If the loam is ordinarily moist to begin with, and also the manure, there is very little likelihood of any of the material getting too dry during the preparation. And much less preparation is needed, for the presence of the loam lessens, considerably, the probability of hasty, violent fermentation.

Mr. Withington, of South Amboy, N. J., uses rather a stinted amount of loam in his manure. He writes me: "We made up our beds this year with a proportion of loam in the manure, say one part loam to eight parts manure, but have always used clear manure heretofore, and I think the beds hold out longer than when only manure is used."

CHAPTER IX.

MAKING UP THE MUSHROOM BEDS.

The place in the cellar, shed, house, or elsewhere, where we intend to grow the mushrooms, should be in readiness as soon as the manure has been well prepared and is in proper condition for use. The bed or beds should be made up at once. The thickness of the beds depends a good deal upon circumstances, such as the quality of the manure,—whether it is plain horse manure, or manure and loam mixed together,—or whether the beds are to be made in heated or unheated buildings, and on the floor or on shelves. Floor beds are generally nine to fifteen inches deep; about nine inches in the case of manure alone, in warm quarters, and ten to fourteen inches when manure and loam are used. In cool houses the beds are made a few inches deeper than this so as to keep up a steady, mild warmth for a long time. The beds may be made flat, or ridged, or like a rounded bank against the wall; but the flat form is the commonest, and the most convenient where shelves are also used in the same building. Shelf beds are generally nine inches deep; that is, the depth of one board.

In making up the beds, bring in the manure and shake it up loosely and spread it evenly over the bed, beating it down firmly with the back of the fork as you go along, and continue in this way until the desired depth is attained. If it is a floor bed and there is no impediment, as a shelf overhead, tread the manure down firmly and evenly; if the manure is fairly dry and in good condition it will be pretty firm and still springy, but if it is too moist and poorly prepared treading will pack it together like wet rotten dung.

Now pierce a hole in the bed and insert a thermometer. There are "ground" or "bottom-heat" thermometers, as gardeners call them, for this purpose, but any common thermometer will do well enough; and after two or three days examine this thermometer daily to see what is the temperature of the manure in the bed. In roomy or airy structures or where only a small bed has been made it may, in the meantime, be left in this condition. But in a tight cellar I find that the warm moisture arising from the bed condenses in the atmosphere and settles on the top of the manure, making it perfectly wet. In order to counteract this, as soon as the bed is made up I spread some straw or hay over it loosely; the moisture settles on the covering and does not reach through to the manure. Beware of overcovering, as such induces overheating inside the bed. At spawning time remove this covering. The bed will then have become so cool (80° or 90°) that there is very little evaporation from it, consequently little danger of surface-wetting.

The Proper Temperature.—This, in mushroom beds, depends upon the materials of which they are composed, their thickness, how they are built, the situation they are in, and other circumstances. If the manure was good and fresh to begin with, carefully prepared and used as soon as ready, the bed in a few days will warm up to 125°, or a little more or less, and this is very good. My best beds have always shown a maximum heat of between 120° and 125°. Had the manure been used a few days too soon the heat would rise higher, perhaps to 135°, but this is too warm; in this case I would fork over the surface of the bed a few inches deep to let the heat escape, and after a couple of days compact the bed again. Boring holes all over the surface of the beds with a crowbar is the common way of reducing a too high temperature, and when the heat has subsided sufficiently fill up these holes with finely pulverized dry loam. With loam we can fill them up perfectly, but we can not do this with manure, and if left open they remain as wet sweat holes that are very deleterious to the spreading spawn.

A too high temperature in the beds should be sedulously guarded against, for it wastes the substance of the manure, dries up the interior of the bed, and the mushroom crop must necessarily be starved and short.

Provided that the manure is fresh and good and has been well prepared, if the beds, after being made up, do not indicate more than 100° or 110° no alarm need be felt, for excellent crops will likely be produced by these beds. The thicker the beds are the higher the heat will probably rise in them. Firmly built beds warm up more slowly than do loosely built ones, and they keep their heat longer. If the materials are quite cool when built solidly into beds they are not apt to become very warm afterward. But I always like to make up the beds with moderately warm manure.

It sometimes happens that circumstances may prevent the making up of the beds just as soon as the manure is in prime condition, and even after they are made up the heat does not rise above 75° or 80°. In such a case if the manure is otherwise in good condition and fresh, it is well enough and a good crop may be expected. But if the manure, to begin with, had been a little stale, rotten and inert, I certainly would not hesitate to at once break up the bed, add some fresh horse droppings to it, mix thoroughly, then make it up again. Or a fair heat may be started in such a stale bed by sprinkling it over rather freely with urine from the barnyard, then forking the surface over two or three inches deep and afterward compacting it slightly with the back of the fork. Spread a layer of hay, straw, or strawy stable litter a few inches deep over the bed till the heat rises. If the manure had been moist enough this sprinkling should not be resorted to, but the fresh droppings added instead. When it is applied, however, great care should be taken to prevent overheating; a lessening or entire removal of the strawy covering, and again firmly compacting the surface of the bed will reduce the temperature. Some saltpeter, or nitrate of soda, an ounce to three gallons of liquid, will encourage the spread of the mycelium after the spawn is inserted; a much stronger solution of these salts can now be used than would be safe to apply after the mycelium is running in the bed.

When loam and manure mixed together comprise the materials of which the bed is made, the temperature is not likely to rise so high as when manure alone is used, but this matters not so long as the materials of which the bed is composed are sweet and fresh and not over-moist. But if the materials are cold and stale treat as recommended for a manure bed, always bearing in mind that it is better to have a cold bed that is fairly dry than one that is wet, or, indeed, a warm one that is wet.

Mr. Withington, of South Amboy, has a good word to say for beds of a low temperature. He writes me: "Our beds kept in good bearing two months, though they have borne in a desultory way a month longer. Our best bed this season was one that was kept at an even temperature. The manure never rose above 75° when made up, and decreased to about 60° soon after spawning. Kept the house at 55°."

CHAPTER X.

MUSHROOM SPAWN.

What is mushroom spawn? Is it a seed or a root? Do you plant it or sow it, or how do you prepare it? are some of the questions asked me now and again. To the general public there seems to be some great mystery surrounding this spawn question; in fact, it appears to be the chief enigma connected with mushroom-growing. Now, the truth is, there is no mystery at all about the matter. What practical mushroom growers call spawn, botanists term mycelium.

The spawn is the true mushroom plant and permeates the ground, manure, or other material in which it may be growing; and what we know as mushrooms is the fruit of the mushroom plant. The spawn is represented by a delicate white mold-like network of whitish threads which traverse the soil or manure. Under favorable circumstances it grows and spreads rapidly, and in due time produces fruit, or mushrooms as we call them. The mushrooms bear myriads of spores which are analogous to seeds, and these spores become diffused in the atmosphere and fall upon the ground. It is reasonable to suppose that they are the origin of the spawn which produces the natural mushrooms in the fields, also the spawn we find in manure heaps. But we never have been able to produce spawn artificially from spores, or in other words, mushrooms have never been grown by man, so far as I can find any authentic record, from "seed." How, then, do we get the spawn? By propagation by division. We take the mushroom plant or spawn, as we call it, and break it up into pieces, and plant these pieces separately in a prepared bed of manure or other material, under conditions favorable for their growth, and we find that these pieces of spawn develop into vigorous plants that bear fruit (mushrooms) in about two months from planting time. When the spawn has borne its full crop of fruit it dies.

Well, then, if we can not produce spawn from spores, and the spawn in the beds that have borne mushrooms has died out, how are we to get the spawn for our future crops? is a question that may suggest itself to the inexperienced. By securing it when it is in its most vigorous condition, which is before it begins to show signs of forming mushrooms, and drying it, and keeping it dry till required for use. But in order to secure the spawn we need to take and keep with it the manure to which it adheres or in which it is spreading. In this way it can be kept in good condition for several years and without its vitality being perceptibly impaired. Keeping it dry merely suspends its growth; as soon as it is again submitted to favorable conditions of moisture and heat its pristine activity returns.

Mushroom spawn can be obtained at any seed store. Our seedsmen always keep it in stock, both the brick (English), and the flake (French) spawn. It is retailed in quantities of one pound or more, and as the article is perfectly dry it can be easily sent by mail in small quantities.

The seedsmen import it from Europe every year along with their seeds. A prominent Boston seedsman writes me: "We get our supply through the London wholesale seedsmen, for the sake of convenience and cheaper ocean freight, etc. Coming with a shipment of other goods and on same bill of lading brings the freight charges down. The low price at which mushroom spawn is sold in quantity can only be maintained with low freight rates, as there is a duty here of 20% on the article."

Fig. 21. Brick Spawn.

By direct inquiry of the leading importers in different cities I find that we import about 4500 lbs of French or flake spawn, and 4000 bushels, or 64,000 lbs of English or brick spawn, and that fully a half of this whole importation is handled by the seedsmen of New York city. In New York one firm alone, who make a specialty of supplying market gardeners, has in one year imported 1500 bushels of brick spawn. But the vicinity of New York is the great mushroom-growing center of the country, also the best market for mushrooms in the country. One gardener at Jamaica, L. I., bought 1000 lbs of brick spawn at one time, and a neighbor of his bought 400 lbs; this shows what a large quantity of spawn market gardeners require. And the demand this year is unprecedented; some of our leading importers had sold out their supply before the first of November. And it is not private growers so much as market growers who are the cause of this; the market men find there is money in growing mushrooms and they are going into it.

Spawn comes in the form of dry, hard, solid manure bricks, and also in the form of flakes of half rotted strawy manure. These bricks and flakes are completely permeated with the mushroom mycelium.

The brick spawn is commonly known as English spawn, and what is imported into this country is made in England, mostly about London. The bricks made by the different manufacturers vary a little in size and weight; in some cases ten bricks go to the bushel, in others fourteen, and in others sixteen. This last is the commonest sized brick, and weighs exactly a pound, and measures about eight and one-half inches long, five and one-fourth inches wide, and one and one-fourth inches thick; it is what the London spawn makers call a 9x6x2 inch brick, but it shrinks in drying. In retailing brick spawn in this country it is sold by weight and not by measure.

Mill-track mushroom spawn is advertised by some of our seedsmen, but what they sell under this name is only the ordinary English brick spawn. One of our prominent seed firms who advertise it write me: "Genuine mill-track spawn used to be the best in England, but it has been superseded, although European gardeners still call for English spawn under the name of 'mill-track.'" The real mill-track spawn is the natural spawn that has spread through the thoroughly amalgamated horse droppings in mill-tracks or the cleanings from mill-tracks. It is usually sold in large, irregular, somewhat soft lumps, and is much esteemed by spawn makers for impregnating their bricks, but nowadays, that horses have given place to steam as a motive power in mills, we have no further supply of mill-track spawn for use in spawning our mushroom beds. We do not feel this loss, however, as the spawn now manufactured by our best makers will produce as good a crop of mushrooms as the old mill-track natural spawn used to do.

The flake spawn is what is generally known as French spawn, and is imported into this country from France. But the manufacture of "French" spawn for sale, however, is not strictly confined to France. It is put up in two ways, namely, nicely packed in thin wooden boxes, each containing two or three pounds of spawn, and also loose in bulk when it is sold by weight or measure.

Fig. 22. Flake or French Spawn.

Virgin spawn is what we call natural spawn or wild spawn; that is, the spawn that occurs naturally in the fields, in manure piles, or elsewhere, and without any artificial aid. It is supposed to be produced directly from the mushroom spores, and is not a new growth of surviving parts of old spawn that may have lived over in the ground. It is far more vigorous than "made" spawn, and spawn makers always endeavor to get it to use in spawning the artificial spawn. It is seldom used for spawning mushroom beds because not easy to obtain. Now and again we come upon a lot of it in a manure pile; it looks like a netted mass of white strings traversing the manure. As soon as discovered secure all you can find, bring it indoors to a loft, shed, or room, and spread it out to dry; after drying it thoroughly keep it dry and preserve and use it as you would French spawn, for it is the best kind of flake spawn. In using virgin spawn for spawning beds I have obtained larger and heavier mushrooms than from "made" spawn, and the beds lasted longer in good bearing, but the weight of the whole crop has not been more than from artificial spawn.

How to Keep Spawn.—Spawn should be kept in a dry, airy place, somewhat dark, if convenient, and in a temperature between 35° and 65°. Wherever things will "must," as in a cellar, cupboard against a wall, or in a close, damp building, is a very poor place for keeping spawn. If the spawn is perfectly dry and kept in a dry, airy place, and not in large bulk, and covered, it will bear a high temperature with apparent impunity, but whenever dampness, even of the atmosphere, is coupled with heat, the mycelium begins to grow, and this, in the storeroom, is ruinous to the spawn. Judging from our natural mushroom crops, the spawn for which must be alive in the ground in winter, one concludes that frost should not be injurious to the artificial spawn, still my experience is that hard frost destroys the vitality of both brick and flake spawn. And this is one reason why I get our full supply of spawn in the fall and keep it myself rather than submit it to the mercy of the seed store.

New Versus Old Spawn.—How long spawn may be kept without its vitality becoming impaired is an unsettled question, but there is no doubt, if properly kept, it will remain good for several years. But I can not impress too strongly upon the reader the importance of using fresh spawn. Do not use any old spawn at any price; do not accept it gratis and ruin your prospect of success by using it. It takes three months from the time when the manure is gathered for the beds until the mushrooms are harvested. Can you, therefore, afford to spend this time, and undergo the care and trouble and expense, and court a failure by using old spawn? We have risks enough with new spawn, let alone old spawn. I do not use any more old spawn, but I have used it often and long enough to be convinced of its general worthlessness, unless preserved with the greatest care.

How to Distinguish Good from Poor Spawn.—This is a very difficult matter, notwithstanding what people may say to the contrary. If we could positively tell good from bad spawn, we would never use bad spawn, and, therefore, with ordinary care, have very few failures in mushroom-growing; for good spawn is the root of success in this business. Spawn differs very much in its appearance; sometimes the bricks show very little appearance of the presence of spawn, and still are perfectly good; and again, we may get bricks that are pretty well interlaced and clouded with bluish white mold or fine threads, and this, too, is good. When the bricks are freely pervaded with pronounced white threads this is no sign that the spawn is bad. Bricks dried as hard as a board may be perfectly good; so, too, may be those that are comparatively soft. Mushroom spawn should have a decided smell of mushrooms, and whatever cobweb-like mold may be apparent should be of a fresh bluish white color, and the fine threads clear white. Prominent yellowish threads or veins are a sign that the mycelium had started to grow and been killed. Distinct white mold patches on the surface of the bricks indicate the presence of some other fungous parasite on the mushroom mycelium; the absence of any mushroom smell in the spawn indicates its worthlessness and that the mycelium is dead. One familiar with mushroom spawn can tell with considerable certainty "very living" spawn and "very dead" spawn, but I am far from convinced that any one can decide unhesitatingly in the case of middling or weak spawn.

Mr. S. Henshaw, in Henderson's Handbook of Plants, tells us: "The quality of the spawn may be very easily detected by the mushroom-like smell, ... and I should have no hesitation in picking out good spawn in the dark." Sanguine, surely, but I have tried it and found the test wanting. M. Lachaume says that good spawn shows "an abundance of bluish-white filaments well fitted together, and giving off a strongly marked odor of mushrooms. All those portions which show traces of white or yellow mold or have a floury appearance, should be rejected and destroyed." Mr. Wright says: "A brick may be a mass of moldiness, and yet be quite worthless; and if the mold has a spotted appearance, as if fine white sand had been dredged on and through the mass, it is certain there is no mushroom-growing power there.... If thick threads pass through the mass and there are signs of miniature tubercles on them, then the spawn may be regarded as too far gone.... Clusters of white specks on the spawn denote sterility."

Mr. A. D. Cowan, of New York, who has the reputation of being an excellent judge of mushroom spawn, writes me: "To correctly judge the quality of brick spawn by its appearance requires experience in handling it, and a trained eye which enables one quickly to detect good from bad, fair to middling. As two lots seldom come exactly or nearly alike in appearance, it is hardly possible to give precise rules to follow, excepting the never-failing requisite which the spawn must possess to be good, namely, the moldy appearance on the surface, the more the better, without showing threads. Too many of these to a given space are a sure indication of exhausted vitality, arising generally from the bricks being heaped together when in process of manufacture, before they are sufficiently dried. Healthy bricks are usually of a dusty brown color, and of light weight. Black colored spawn is to be avoided, as a rule, and when the black appearance is very prevalent in a cargo of bricks it is a strong indication that the spawn has not run its course; and as it is not expected to do so after it has reached the hands of the retailer it is economy to cast it aside. Some persons break a brick into several pieces to see how it looks inside. To the experienced eye this is not necessary, or even to lay hands upon it, as the outward moldy appearance is the best of all evidence of its healthy vitality, and this never exists if the bricks have lost their germinating power, excepting, of course, where they have been kept damp, and the spawn has spent its power, which is detected by the white threads appearing in great quantity."

American-made Spawn.—So far as I have been able to find out by diligent inquiry, mushroom spawn is not made for sale in this country. But I am informed that a few growers do save and use their own flake spawn. Some of our principal growers, Van Siclen, Gardner, and Henshaw, for instance, in time past attempted to make their own spawn, but with only partial success, and now they confine themselves to the imported article. But this state of affairs can not long continue. The demand here for fresh mushrooms is so great, the industry of mushroom-growing so important, the price of imported spawn so high, and the quantity of foreign spawn imported annually into this country is so large, that, before long, we hope some one will find it to his advantage to make a specialty of growing mushroom spawn in this country to supply the American market. There is no practical operation in connection with the cultivation of mushrooms so little known or understood by the general grower as the growing (or "making," as it is commonly called) and preserving of mushroom spawn. General cultivators in England and France (outside of the Paris caves) do not make their own spawn; it is a distinct branch of the business, and carried on by specialists who grow mushrooms for sale in winter, and spawn in summer.

The time and attention required to produce a small quantity of first-class spawn are worth more than the cost of the spawn at the seed store. In order to make spawn profitably we must make it in large quantity, and we need not attempt to make it unless we have good materials and conditions for its proper preparation, and will give it every attention possible for its best development.

Because spawn may be made in America is no reason whatever why the American people will buy it. We must produce, at least, as good an article as the best in Europe before we can find countenance in our home market. It is not the shape of the manure brick, its size, fine finish, hardness, softness, or freshness, that counts in this case; it is the fullness and vitality of the mass of mycelium or mushroom plant that is contained within it.

HOW TO MAKE BRICK SPAWN.

As the making of brick spawn for sale is not yet an American industry, but almost entirely confined to England, I think it best to restrict myself to describing how it is made in England. Mr. John F. Barter, of Lancefield street, London, is one of the most successful mushroom growers and spawn makers in Great Britain. He writes me that he confines himself entirely to the mushroom business; he makes his living by it. He grows mushrooms in the winter months and makes spawn in the summer months; he employs men for mushroom bed making from August until March, then, to keep on the same hands during summer, he makes spawn for sale. He grows for and sells in the London market about 21,000 pounds of mushrooms a year, and in summer makes some 10,000 bushels, equal to 160,000 pounds, of brick spawn for sale. The amount of spawn made in a year by this one manufacturer is about three times as much as the total annual importation of mushroom spawn of all kinds into this country. And he is only one maker among several. This fact alone must convince us that mushroom-growing is carried on to a vastly greater extent in European countries than it is here, where we have as good facilities as they have, and an immensely better market.

The manner of making the spawn differs a little with the different manufacturers, and no one can become proficient in it without practical knowledge. I asked Mr. Barter if he thought spawn could be made profitably in this country, paying, as we do, $1.50 a day for laborers, and without any certainty of the same men staying with us permanently. He writes me: "Uncertain labor would be of no use. Of course the wages you pay would not affect it much, as I pay nearly as much as that for my leading men. But to begin with, you must have a man that has had some experience."

About the simplest and best way of making brick spawn that I find described is the following from The Gardeners' Assistant. I may here state that Robert Thompson, the author of this work, was for many years the superintendent of the Royal Horticultural Society's gardens at Chiswick, near London, and, in his day, was regarded as without a peer in practical horticulture, and lived in the midst of the market gardens of London and the principal mushroom-growing district.

"Fresh horse droppings, cow dung, and a little loam mixed and beaten up with as much stable drainings as may be necessary to reduce the whole to the consistence of mortar. It may then be spread on the floor of an open shed, and when somewhat firm it may be cut into cakes of six inches square. These should be placed on edge in a dry, airy place, and must be frequently turned and protected from rain. When half dry make a hole in the broadside of each, large enough to admit of about an inch square of good old spawn being inserted so deep as to be a little below the surface; close it with some moist material the same as used in making the bricks. When the bricks are nearly dry make, on a dry bottom, a layer nine inches thick of horse dung prepared as for a hotbed, and on this pile the bricks rather openly. Cover with litter so that the steam and heat of the layer of dung may circulate among the bricks. The temperature, however, should not rise above 60°; therefore, if it is likely to do so, the covering must be reduced accordingly. The spawn will soon begin to run through the bricks, which should be frequently examined whilst the process of spawning is going on, and when, on breaking, the spawn appears throughout pretty abundantly, like a white mold, the process has gone far enough. If allowed to proceed the spawn would form threads and small tubercles, which is a stage too far advanced for the retention of its vegetative powers. Therefore, when the spawn is observed to pervade the bricks throughout like a white mold, and before it assumes the thread-like form, it should be removed and allowed to dry in order to arrest the further progress of vegetation till required for use. It ought to be kept in a dark and perfectly dry place." I would add, do not keep it where it is apt to become musty or moldy in summer; also keep it in as cool a dry place as possible in summer, and always above 35° in winter.

These other recipes are also given:

"1. Horse droppings one part, cow dung one-fourth, loam one twentieth.

"2. Fresh horse droppings mixed with short litter one part, cow dung one-third, and a small portion of loam.

"3. Equal parts of horse dung, cow dung, and sheep's dung, with the addition of some rotten leaves or old hotbed dung.

"4. Horse dung one part, cow dung two parts, sheep's dung one part.

"5. Horse droppings from the roads one part, cow dung two parts, mixed with a little loam.

"6. Horse dung, cow dung, and loam, in equal parts."

From the above it appears that horse dung and cow dung are the principals in spawn bricks; the loam is added for the purpose of making the other materials hold together; it also absorbs the ammonia, which otherwise would pass off.

J. Burton's Method. From The Kitchen and Market Garden.—Make the spawn in early spring. As cow manure is the principal ingredient used in making the bricks this should be secured before the animals get any green food. Store it on the floor of an open, dry, airy shed, and turn it every few days for a week or two. Then add an equal part of the following: Fresh horse droppings, a little loam, and chopped straw, mixed together. "The whole should then be worked well together and then trodden down, after which it may be allowed to remain for a few days, when it will be required to be turned two or three times a week. If the weather be fine and dry the mass will soon be in a fit condition for molding into bricks, which process can be performed by using a mold in the same way as the brick makers, or, ... the manure may be spread evenly on the floor to a thickness of six inches, and then be firmly trodden and beaten down evenly with the back of the spade. It should then be lined out to the required size of the bricks, and be cut with a sharp spade or turfing iron. In a few days the bricks will be sufficiently dry to handle, when they should be set up edgeways to dry thoroughly, and if exposed to the sun for two or three days they will be ready to receive the spawn. In introducing the spawn two holes large enough to admit a piece of spawn as big as a pigeon's egg should be cut in each brick at equal distances. This should be well beaten in and the surface made even with a little manure. The bricks should then be collected together in a heap and covered with enough short manure to cause a gentle heat, being careful that there is no rank heat or steam to kill the spawn. This must be carefully attended to until the spawn is found to have penetrated through the whole of the bricks, after which they should be stacked away in any convenient dry place."

HOW TO MAKE FRENCH (flake) SPAWN.

I can not do better than to let a practical Frenchman engaged in the business tell this story. In Vol. XIII of the London Garden I find an English translation of M. Lachaume's book, "The Cave Mushroom," and this comment by the editor: "The most complete account of the cave culture of mushrooms which has been published by any cultivator on the spot well acquainted with the subject is that recently published by M. Lachaume."

Lachaume says: "The best spawn to use is what is called 'virgin spawn'; that is to say, which has not yet produced mushrooms. In this country this kind of spawn may be procured of any respectable nurseryman, under the name of 'French spawn.' It differs from English spawn by being in the form of small tufty cakes, instead of in compact blocks. Large mushroom growers, however, always provide themselves with their own spawn by taking it from a bed which is just about to produce its crop, or which has already produced a few small mushrooms.... It is true that by thus 'breeding in and in,' as it were, the mushrooms show a tendency to deteriorate after a time; new spawn must therefore be obtained as soon as any signs of deterioration begin to manifest themselves."

Making French Virgin Spawn.—Condensed from Lachaume's book on mushrooms. Take five or six barrow loads of horse droppings that have lain in a heap for some time, and lost their heat, and mix them with one-fourth of their bulk of short stable litter. Then, in April, open a trench two feet wide, twenty inches deep, and length to suit, at the foot of, but eight inches distant from, a wall facing north. In the bottom of the trench spread a layer three to four inches deep of chopped straw, then an equally thick layer of the prepared manure, all pressed firmly by treading it down. The two layers must now be gently watered, and then another double layer of chopped straw and droppings must be laid, trodden down and watered, and so on until the top of the trench is reached. The bed ought to rise above the level of the ground and be rounded off like the top of a trunk. To prevent excessive dampness from heavy rain cover the mound with a thick layer of stable litter. Three months after filling the trench it should be opened at the side or end. If the pieces of manure are well covered with masses of bluish-white filaments, giving off the odor of mushrooms, the operation has succeeded, and the spawn is fit for use or for drying to preserve for future use. But if the threads are only sparingly scattered through the mass, the trench should be covered up again and left for another month. In saving the spawn the flakes of manure containing the largest amount of spawn filaments should be retained, and those showing a brown appearance rejected. In order to facilitate the drying of the spawn the flakes should be broken into pieces, weighing from one to two pounds; they are then placed in a well ventilated shed, but they must not be piled upon each other. Properly prepared and dried this spawn keeps good for ten years.

A Second Method (by Lachaume). "This is generally adopted by mushroom growers. The formation of the spawn is accelerated by adding pieces of old spawn here and there.... At the beginning of April we must choose a piece of ground situated at the foot of a wall facing north.... The soil ought to be very open and light rather than heavy, so as to avoid dampness. Taking advantage of a fine day, we open a trench sixteen inches wide and at about eight inches from the foot of the wall, and of a length adapted to the quantity of spawn we desire to produce. The earth is thrown out on the side opposite the wall. Manure which has been prepared for a mushroom bed, and has just come into condition is then filled into the trench, leaving, however, a space at one end of it about two feet and six inches in length for the formation of a mushroom bed, which is made by tossing the manure about and shaking it up with the hands, after which it is pressed down with the hands and knees. As soon as the layer of manure reaches six inches in thickness we place along the edge a number of lumps of spawn at about one foot apart. These lumps are placed level with the manure on the edge facing the wall. This portion of the surface of the manure ought to be raised vertically, and should lean against the earthen wall of the trench. The other half of the surface ought to slope gently toward the wall, leaving a space of three or four inches between it and the side of the trench, so that it may be trimmed. The lumps of spawn on this surface should be placed a little backward, so that they may not be broken when the bed is trimmed. The bed is then covered with more manure, until the first lumps of spawn are buried three or four inches deep. A second row of lumps of spawn is then inserted, as described in the directions for making the first row, and the bed is filled up level with the surface of the soil. It is finished by covering it up with a layer of fine, dry soil three or four inches thick. The spawn ought to be very dry, otherwise we shall get a premature crop of mushrooms instead of fresh spawn. At the end of six weeks or a couple of months the new spawn ought to make its appearance, a fact which we may learn by opening the bed. One sign, which will save us the trouble of opening up the beds, is the appearance of young mushrooms on the surface. The layer of earth is first removed, and then the cakes of spawn are treated as described in the directions given for the first method of making spawn."

Third Method (by Lachaume). "By filling in a trench like that described in the first method, by a series of layers of one-third of pigeon or fowl guano, and two-thirds of short manure, containing a large proportion of spent horse droppings, treading it down firmly, watering it if it is too dry, and finishing up with a layer of soil, as described already, we may, at the end of a couple of months, or even a little longer, procure a supply of well-formed cakes of spawn of excellent quality, which may be used in the ordinary manner."

From Mr. Robinson's "Mushroom Culture." "This (French) spawn is obtained by preparing a little bed, as if for mushrooms, in the ordinary way, and spawning it with morsels of virgin spawn, if that is obtainable; and then when the spawn has spread through it, the bed is broken up and used for spawning beds in the caves, or dried and preserved for sale."

From Mr. Wright's book on mushrooms. "French spawn ... is contained in flakes of manure. Neither is it virgin spawn, nor derived immediately from it, ... but is spawn taken from one bed for impregnating another."

Relative Merits of Flake and Brick Spawn.—The flake or French spawn costs about three times as much as the brick or English spawn, and, as it is so much whiter with mycelium than is the brick spawn, many believe that it is more potent and well worth the additional cost. In spawning the beds I use two pounds of flake spawn to plant the same space for which I would use five pounds of brick spawn, and this gives a capital crop, with number of mushrooms a little in favor of the flake spawn, but on account of the larger size of the mushrooms the weight of crop is considerably in favor of the brick spawn. And I find more certainty of a crop in the case of the brick spawn than in the other.

Regarding the respective merits of brick and flake spawn, Mr. Barter, in response to my inquiry, writes me: "I have tried them both, and know brick spawn to be far the best. You see, I do nothing but this mushroom business for a living, so, of course, would use the best kind of spawn for my crop. Generally the French spawn produces one-third less mushrooms than does the brick spawn from the same length of bed, besides, those from the brick spawn are by far the heaviest and fleshiest."

I would here observe that Mr. Barter's remarks apply more to ridge beds out of doors than beds in the cellar or mushroom house. And it is odd, but true, that the flake spawn does not produce as good results in outdoor beds as it does in those under cover.

CHAPTER XI.

SPAWNING THE BEDS.

After the mushroom bed is made up it should, within a few days, warm to a temperature of 110° to 120°. Carefully observe this, and never spawn a bed when the heat is rising, or when it is warmer than 100°, but always when it is on the decline and under 90°. In this there is perfect safety. Have a ground thermometer and keep it plunged in the bed; by pulling it out and looking at it one can know exactly the temperature of the bed. Have a few straight, smooth stakes, like short walking canes, and stick the end of these into the bed, twelve to twenty feet apart; by pulling them out and feeling them with the hand one can tell pretty closely what the temperature of the bed is.