Espoma Organic Garden Gypsum

Gypsum is the clay-soil secret weapon that too few homeowners know about. When you have heavy clay that gets compacted, poorly drained, and crusty after rain, gypsum delivers calcium and sulfur ions that displace sodium and magnesium from clay particles, allowing them to aggregate into larger clumps — a process called flocculation. The result is better drainage, more air pockets for roots, and soil that works like soil instead of modeling clay. Espoma Garden Gypsum is the reference-standard product in this category: 100% natural mined calcium sulfate, no fillers, OMRI-listed organic. Critically, gypsum does NOT alter soil pH — unlike lime or sulfur, you can apply it alongside a liming program without worrying about overcorrecting pH. Apply at 36 lbs per 1,000 sq ft for heavy clay; water in thoroughly. You'll notice improved water penetration within one growing season. For the Midwest and Mid-Atlantic clay soil lawns, gypsum is often the missing piece that explains why the lawn never quite responds to fertilizer and seed — the soil structure is too tight for roots to grow well.