Mushroom Compost is a dark, rich, moist mixture of wheat straw, peat moss, cottonseed meal, cottonseed hulls, corncobs, cocoa bean shells, gypsum, lime, chicken litter and/or horse stable bedding. This combination of ingredients is used in commercial mushroom farms to grow mushrooms. These materials are composted for many weeks and then placed into a huge room, where it is completely sterilized. After the sterilization is complete, the compost is then placed into growing trays, where the mushroom growing cycle begins.
Strangely enough, mushrooms can only be grown in this mixture for a short period of time. At this time the compost has to be removed. Not because it is nutritionally depleted, but because the growing environment is very dark and moist and could be subject to invasion by fungi and bacteria. This could be devastating to the mushroom farm. After 18-20 days, the compost is removed, and a brand new batch is prepared for the next crop. The mushroom compost is loaded from the growing trays directly into huge trucks and then shipped. It never touches the ground until it arrives at your facility.