This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Many persons who have a fancy for these are deterred from attempting to cultivate them from the supposed difficulty. They are so easily raised, that any one having the convenience of a dry cellar may have them in profusion. The requisites are, short stable manure, and good mushroom spawn. The manure must be prepared by being frequently turned, so as to prevent excessive heating, and the bed made from six to sixteen inches in thickness, according to the temperature that can be maintained. Where the temperature can be kept up to 60o, the former thickness will be sufficient. The latter thickness will generate sufficient warmth of itself. Insert the spawn when the heat is about 80°, and cover with two inches of soil, firmly beaten, all over the bed. A covering of straw will be necessary should the heat decline. Under the staging of a greenhouse, if protected from the drippings of the pots, or in large pots or boxes, mushrooms may be grown without much trouble or expense.
These valuable esculents may be propagated with greater advantage than by the old mode; the spawn may be broken fine, the largest bits not exceeding a marble in size. Thus prepared, sow it over the surfaoe of the bed, and beat it down at once firmly, and cover it with soil. This plan will require but half the quantity of spawn, and the mushrooms are diffused over the whole surface, no loss being sustained in gathering. They produce sooner by this mode. We have had good success, the present winter, with spawn obtained from the Messrs. Thorbum, N. Y., after failing utterly with that from others.