Gypsum (Calcium Sulfate) is a premium mined agricultural soil amendment that supplies 22.5% calcium and 18% sulfur from natural calcium sulfate dihydrate (CaSO₄·2H₂O) at 97% purity. Unlike lime, gypsum delivers calcium without raising soil pH, making it the right choice for soils where pH is already adequate or alkaline.
Gypsum works through three independent mechanisms: it supplies plant-available calcium for cell walls and root structure, it helps loosen heavy clay soils by flocculating clay particles into larger aggregates for better drainage and air movement, and it displaces sodium in sodic soils where drainage allows the sodium to leach away. It also provides sulfur for protein and chlorophyll synthesis. This makes it well suited to clay-soil lawns and gardens, calcium-sensitive crops such as tomatoes, peppers, brassicas, and peanuts, orchards, and sodic-soil reclamation.
Broadcast with a spreader and water in, or incorporate into the top several inches for the fastest structural response. Gypsum carries no burn risk at recommended rates and can be applied year-round. It is only moderately soluble, so it is not suited to foliar spraying or hydroponic use.
CDFA registered and third-party lab tested for heavy metals, with results consistently well below required limits.