I am officially in love with mushroom compost and instead of buying it I want to start making my own. I was told it consist of horse manure, hay, straw and mushrooms. The way this compost improves my soil's structure is unbelievable! - retains moisture - boost fertility - rich in nitrogen, phosphorus, calcium and potassium - prevents blossom end rot in tomatoes - acts as soil conditioner suppressing weeds - effective at repairing and conditioning heavy clay soils NOT GOOD FOR ACID-LOVING PLANTS! Only downfall for me as I grow berries