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.Read more at Gardening Know How: Mushroom Compost Benefits: Organic Gardening With Mushroom
 
Mushroom compost is suitable for most garden plants. It supports various types of plant growth, from fruits and vegetables to herbs and flowers.