What is Mushroom Compost?

Mushroom compost is a type of slow-release, organic plant fertilizer. The compost is made by mushroom growers using organic materials such as hay, straw, corn cobs and hulls, and poultry or horse manure. Since the mushroom growing process varies slightly between individual growers, mushroom compost recipes may differ here and there. For instance, additional materials like gypsum, peat moss, lime, soybean meal, and various other organic items may be added to the compost as well.