Figure 238.—View in packing room, Akron "tunnel," N. Y. Mushroom Co.; placing mushrooms in basket. Copyright.

There are several reasons why the larger mushrooms are not considered so desirable or marketable as the medium-sized or smaller ones. In the first place, the larger mushrooms, under certain conditions, especially those grown in house culture at a comparatively high temperature, are apt to be very ripe, so that the gills are black from over-ripe spores, and are thus somewhat unsightly. Those grown at a lower temperature, as is the case in some mines, do not blacken so soon, and are therefore apt to be free from this objection. Another objection, however, is on the part of the restaurant owner where mushrooms are served. In serving the mushrooms broiled on toast, the medium-sized one is more desirable from the standpoint of the restaurant owner, in that two medium-sized ones might be sufficient to serve two persons, while one quite large one, weighing perhaps the same as the two medium ones, would only be sufficient to serve one person at the same price, unless the large mushroom was cut in two. If this were done, however, the customer would object to being served with half a mushroom, and the appearance of a half mushroom served in this way is not attractive.

Resoiling.—Once or twice a week during the harvesting period all loose earth, broken bits of spawn, free buttons, etc., should be cleaned out where the mushrooms have been picked. These places should be filled with soil and packed down by hand. All young mushrooms that "fog off" should be gathered up clean. Some persons follow the practice of growing a second crop on the same bed from which the first crop has been gathered. The bed is resoiled by placing about two inches of soil over the old soil. The bed is then watered, sometimes with lukewarm water to which a small quantity of nitrate of soda has been added. The large growers, however, usually do not grow a second crop in this way, but endeavor to exhaust the material in the bed by continuous growth.

Use of manure from beds which have failed.—Manure in which the spawn has failed to run is sometimes removed from the bed and mixed with fresh manure, the latter restoring the heat. If the manure was too wet, the moisture content can now be lessened by the use of dry soil.

Cleaning house to prepare for successive crops.—When the crop is harvested, all the material is cleaned out to prepare the beds for the next crop. The material is taken out "clean," and the floors, beds, walls, etc., swept off very clean. In addition, some growers whitewash the floors and all wood-work. Some whitewash only the floors, depending on sweeping the beds and walls very clean. Still others whitewash the floors and wash the walls with some material to kill out the vermin. Some trap or poison the cockroaches, wood-lice, etc., when they appear. Some growers who succeed well for several years, and then fail, believe that the house "gets tired," as they express it, and that the place must rest for a few years before mushrooms can be grown there again. Others grow mushrooms successfully year after year, but employ the best sanitary methods.

Number of crops during a year.—In caves or mines, where the temperature is low, the beds are in process of formation and cropping continuously. So soon as a bed has been exhausted the material is cleaned out, and new beds are made as fast as the fresh manure is obtained. In houses where the mushrooms cannot be grown during the summer, the crops are grown at quite regular periods, the first crop during fall and early winter, and the second crop during spring. Some obtain the manure and ferment it during August and September, spawning the beds in September and October. Others begin work on the fermentation of the manure in June or July, make up the beds in July and August, spawn, and begin to draw off the crop somewhat earlier. The second crop is prepared for whenever the first one is drawn off, and this varies even in the experience of the same grower, since the rate of the running of the spawn varies from time to time. Sometimes the crop begins to come four or five weeks from the time of planting the spawn. At other times it may be two or three months before the spawn has run sufficiently for the crop to appear. Usually the crop begins to come on well in six to eight weeks. The crop usually lasts for six weeks to two months, or longer.

Productivity of the beds.—One pound of mushrooms from every two square feet of surface is considered a very good crop. Sometimes it exceeds this, the beds bearing one pound for every square foot, though such a heavy yield is rare. Oftener the yield is less than half a pound for a square foot of surface.

Causes of failure.—The beginner should study very carefully the conditions under which he grows his crops, and if failure results, he should attempt to analyze the results in the light of the directions given for the curing of the manure, its moisture content, "sweetness," character of the spawn, temperature, ventilation, etc. While there should be good ventilation, there should not be drafts of air. A beginner may succeed the first time, the second or third, and then may fail, and not know the cause of the failure. But given a good spawn, the right moisture content of the material at time of planting and running of the spawn, the sweet condition, or proper condition of the curing of the manure, proper sanitary conditions, there should be no failure. These are the most important conditions in mushroom culture. After the spawn has run and the crop has begun to come, the beds have been known to freeze up during the winter, and in the spring begin and continue to bear a good crop. After the spawn has run well, beds have accidentally been flooded with water so that manure water would run out below, and yet come on and bear as good a crop as adjoining beds.

Volunteer mushrooms in greenhouses.—Volunteer mushrooms sometimes appear in greenhouses in considerable quantity. These start from natural spawn in the manure used, or sometimes from the spawn remaining in "spent" mushroom beds which is mixed with the soil in making lettuce beds, etc., under glass. One of the market gardeners at Ithaca used old spawn in this way, and had volunteer mushrooms among lettuce for several years. In making the lettuce beds in the autumn, a layer of fresh horse manure six inches deep is placed in the bottom, and on this is placed the soil mixed with the old, spent mushroom beds. The following year the soil and the manure at the bottom, which is now rotten, is mixed up, and a fresh layer of manure is placed below. In this way the lettuce bed is self-spawned from year to year. About every six years the soil in the bed is entirely changed. This gardener, during the winter of 1900–1, sold $30.00 to $40.00 worth of volunteer mushrooms. Another gardener, in a previous year, sold over $50.00 worth.