Jonathan Green 15,000 sq. ft. Coverage Mag-I-Cal Fertilizer. This highly soluble form of calcium rapidly raises soil pH, making it ideal for lawns in acidic soil. It enhances lawn fertilizer performance, boosts lawn color, and aids in water uptake. This pelletized fertilizer is easy to spread and can be used throughout the entire yard and garden. It is safe to apply when seeding or sodding and can be applied at any time and in combination with any other product.