← Liquid gypsum FAQ

Is liquid gypsum good for lawns?

By Joe, Founder of Dr Forest · June 2026

Is liquid gypsum good for lawns?

Yes, particularly on clay. Because it works without digging in, liquid gypsum is one of the few ways to get calcium down to the root zone under an established lawn and to ease surface capping that makes turf sit wet. Apply 10 ml per litre at 1 litre per square metre monthly, or 15 ml per litre every two weeks on heavy clay.

A lawn over clay often struggles because the surface seals and rain cannot drain, so the grass sits in a cold, airless mat. You cannot dig the soil without lifting the turf, which is exactly the situation a watered-on calcium feed is suited to. It is especially useful straight after aeration or scarifying, when holes and channels let it travel down quickly, and on newly laid turf or fresh overseeding to support establishment. Be realistic about the limits, though. If a lawn is waterlogged because of a buried pan or a high water table, gypsum will not fix the underlying drainage, and that is a job for aeration or a proper drainage scheme.