This section is from the book "The Gardener's Monthly And Horticulturist V23", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The manure of horses and mules is the only kind which can be successfully used in the cultivation of these plants.
In preparing the manure for the beds, it ought to be free from coarse straw or other coarse material, and must undergo a process of fermentation, which is obtained by piling it in beds of sufficient thickness to heat, which in six or eight days can be worked over. Care must be taken to have that nearest the outside incorporated in the middle of the heap, so that it will all be mixed and attain an equal condition all through the heap. Two or three such mixings at intervals of a week is generally enough to have it in condition to be put in beds for the reception of the seed. Care must be exercised as to the moisture or dryness of the manure while undergoing the process of fermentation. In all cases, it should be neither so wet as to be pressed in balls, by the hand, nor so dry as to burn, or what is called fire fang.
Beds on shelves or benches should have at least from twelve to fifteen inches space between them, so as to conveniently perform all necessary work, and should incline towards their front, and should not be over two and a half to three feet wide for shelves, or five feet for benches. The prepared manure must be evenly put on beds and compactly put down so as to be of equal consistency or solidity. After the finishing the beds should be covered with cut straw four or five inches in thickness, so as to hasten on a higher temperature, which in a few days will have reached from 15° to 16° R., which is high enough for setting or planting the seed, provided it is still rising; but must never reach above 26°R., or else the spawn will burn up.