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.