Mushrooms

by William Falconer

All practical mushroom growers know that if the temperature of a twelve inch thick bed at seven inches from the surface is 100°, that within an inch of the surface of the bed will only be about 95° indoors, and 85° to 90° out of doors. Also, that when the heat of the manure is on the decline it falls quite rapidly, five, often ten degrees, a day, till it reaches about 75°, and between that and 65° it may rest for weeks.

Some years ago I gave considerable attention to this matter of spawning beds at different temperatures. Spawn planted as soon as the bed was made (five days after spawning the heat in interior of bed ran up to 123°) yielded no mushrooms, the mycelium being killed. The same was the case in all beds where the spawn had been planted before the heat in the beds had attained its maximum (120° or over). Where the heat in the middle of the bed never reached 115°, the spawn put in when the bed was made, and molded over the same day, yielded a small crop of mushrooms. A bed in which the heat was declining was spawned at 110°; this bore a very good crop, and at 100° and under to 65° good crops in every case were secured, with several days' delay in bearing in the case of the lowest temperatures. But notwithstanding these facts, my advice to all beginners in mushroom growing is, wait until the heat of the bed is on the decline and fallen to at least 90°, before inserting the spawn.

Writing to me about spawning his beds, Mr. Withington, of New Jersey, says: "I believe a bed spawned at 60° to 70°, and kept at 55° after the mushrooms appear, will give better results than one spawned at a higher temperature, say 90°."

Fig. 23. Brick Spawn Cut in Pieces for Planting.

Preparing the Spawn.—If brick spawn is used cut up the bricks (standard size) into ten or twelve pieces with a sharp hatchet, and avoid, as much as possible, making many crumbs, as is the case generally when a hammer or mallet is used in breaking the bricks. Extra large pieces of spawn are apt to produce large clumps of mushrooms, but this is not always an advantage, as when many mushrooms grow together in a clump they are apt to be somewhat undersized, and in gathering we can not pluck them all out clean enough so as not to leave a part of the "root" in the ground to poison the balance of the clump, in cases where several or many of them spring from one common base.

Inserting the Spawn.—When brick spawn is used plant the lumps about an inch deep under the surface of the manure, and about ten inches apart each way. If the spawn looks very good, and the lumps are large do not plant them quite so close as when the spawn shows less mycelium in it, and the lumps are small. Never use a dibber in planting spawn; simply make a hole in the manure with the fingers, insert the lump and cover it over at once, and as soon as the bed has been planted firm it well all over. Although the lumps are buried only an inch deep under the manure, we have to make a hole three or four inches deep to push the lump into to get it buried.

French or flake spawn is inserted in much the same way and at about the same distance, only, instead of cutting it up into lumps, we merely break it into flaky pieces about three inches long by an inch thick, and in planting it in the beds, in place of pushing it into the hole, lay in the flake on its flat side and at once cover it.

Many growers plant spawn a good deal deeper than I do, but I have never found any advantage in deep planting. In moderately warm beds, or beds that are likely to retain their heat for a considerable time, I am satisfied that shallow planting is better than deep planting. When we want to mold over our beds soon after spawning them, shallow planting is to be recommended. But if the beds are only 75° to 78°, before being spawned; then I think deep planting is better than shallow planting, because the genial temperature gives the mycelium a better start in life than would the cooler manure nearer the surface.