Garden GypsumEspoma Garden Gypsum is an all natural mineral that can help loosen clay soils, minimize salt damage to plants, and help promote root growth. Pelletized for easy application. Loosens heavy clay soils. Helps cure turf burns from ice melters and pets. Available in 6 and 36 lb. sizes 1 lb. equals 1 cups HOW TO USE Garden Beds: Apply 6 lbs. per 30 square feet into top 6 inches of soil Shrubs: Apply 3 lbs. (5 cups) per plant Flowers: Apply 1 lb. (1 cups)