Mushroom Compost Mushroom compost is a nutrient-rich organic soil amendment made from a blend of decomposed materials such as straw, hay, manure, gypsum, and other organic matter used in mushroom farming. After the mushroom-growing process, the compost is aged and processed into a highly beneficial soil conditioner that enhances soil structure, improves moisture retention, and boosts microbial activity. It is ideal for vegetable gardens, flower beds, and lawn enrichment, helping to promote strong root development and healthy plant growth. Coverage per Cubic Yard One cubic yard of mushroom compost typically covers approximately: 100-150 square feet at a 2-inch depth 75-100 square feet at a 3-inch depth Coverage may vary depending on soil type and application methods. *For orders of more than one material, call our store at (630) 365-8888.