Hi-Yield Fast Acting Gypsum is a much faster solution for loosening compacted soil than gypsums of the past. It's our choice to repair heavy clay soils, and also salt damaged soil. Fast Acting Gypsum quickly improves soil structure; allowing better air and water penetration and promoting better root development and growth with calcium and sulfur. Also reduces soil loss. Use on lawns, vegetable gardens, flower gardens and ornamental beds. Apply any time of year, but spring and fall are best. Pelletized for clean and easy application. 25 lb. bag. Covers 5,000 sq. ft. Always read and follow package directions.