Liquid gypsum: your questions, answered
Liquid gypsum · FAQ
Liquid gypsum: your questions, answered
By Joe, Founder of Dr Forest · June 2026
Everything gardeners ask us about liquid gypsum, with straight answers and the rates we actually use.
Liquid gypsum is micronised calcium sulphate suspended in water: a calcium and sulphur feed that does not change soil pH and helps dispersive clay drain. It is honest about its limits, so on ordinary non-sodic clay the structural effect is modest and organic matter does the lasting work. Pick a question below for the full answer.
What is liquid gypsum? →Micronised natural calcium sulphate, suspended in water with fulvic acid.What does liquid gypsum do? →Feeds calcium and sulphur, and helps dispersive clay drain, without changing pH.How does liquid gypsum work? →Calcium flocculates dispersed clay so water gets through. Strongest on dispersive clay.Does liquid gypsum work on clay soil? →On dispersive clay, yes. On ordinary non-sodic clay, the structural effect is limited.What is clay breaker made of? →Gypsum (calcium sulphate), water and fulvic acid. Nothing else.How do you apply liquid gypsum? →Shake, dilute, water on. Clay soil: 15 ml/L at 1 L/m² every two weeks at first.How often and when should you apply liquid gypsum? →Fortnightly on clay for three months, then monthly. Lawns monthly, March to October.How long does liquid gypsum take to work? →Dissolves in hours; drainage can improve in a season. The structural effect is temporary.Is liquid gypsum good for lawns? →Yes, especially on clay, because it works without digging in. Rates inside.How is liquid gypsum different from granular or powdered gypsum? →Same mineral, calcium sulphate. The liquid is faster and needs no digging in.Does liquid gypsum change soil pH? →No. Gypsum is pH-neutral, unlike lime. Use lime if you need to change pH.Is liquid gypsum safe for pets and children? →A benign mineral. Safe once a drench has soaked in or a spray has dried.Can you use too much liquid gypsum? →You can. Stick to the rates, and do a jar test to check gypsum has a job to do.
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Where to buy liquid gypsum in the UK
19.55% calcium and 15.31% sulphur, milled to 5 microns and handcrafted in Stockport. A calcium and sulphur feed that does not change soil pH.
See rates and sizes★★★★★ 5-star across all platforms · 3,250 reviews · See the Liquid Gypsum page.