← Liquid gypsum FAQ

How do you apply liquid gypsum?

By Joe, Founder of Dr Forest · June 2026

How do you apply liquid gypsum?

Shake the bottle well, dilute the concentrate in water, and apply it as a soil drench or through a watering can. For clay soil, use 15 ml per litre at 1 litre per square metre every two weeks for the first three months, then 10 ml per litre monthly. It needs no digging in, which is what makes it useful under established lawns and borders.

The rate depends on the job. The table below is the full set we recommend. Always water it onto soil that is already moist, and water in after a drench so the calcium moves down to the roots rather than drying on the surface. If you are putting it through a fine spray nozzle, filter it first through a 200 micron mesh, because it is a real mineral suspension. It mixes happily with the rest of the Dr Forest liquid range, so you can fold it into your normal feeding rather than making a separate trip round the garden.

Use	Rate	How often
Clay soil, initial (months 1–3)	15 ml / litre at 1 L/m²	Every 2 weeks
Clay soil, maintenance (month 4 on)	10 ml / litre at 1 L/m²	Monthly
Lawn, general	10 ml / litre at 1 L/m²	Monthly, March–October
Lawn, clay improvement	15 ml / litre at 1 L/m²	Every 2 weeks for 3 months, then monthly
Root drench, general	1 tsp (5 ml) / litre	Every 2–4 weeks
Root drench, active deficiency	2 tsp (10 ml) / litre	Weekly until resolved, then fortnightly
Foliar spray	5 ml / litre	Weekly during fruit set and fill

Dr Forest recommended rates for Liquid Gypsum. Apply to moist soil and water in. Shake well before use.