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.