Winstone Gypsum Clay Breaker 8 kg
Winstone Gypsum Clay Breaker is a bagged natural gypsum (calcium sulphate) for loosening clay and compacted garden soil. It adds calcium and sulphur without changing pH, so it suits vegetables, flowers, fruit trees, lawns and acid loving natives alike. This is the 8 kg bag.
At a glance
- Type: amendment (calcium sulphate, clay breaker)
- Use for: heavy clay, compacted soil, calcium and sulphur without a pH change
- Rate: not printed on this page; follow the rate on the Winstone bag
- Pack: 8 kg bag
- Also available: 25 kg bag
What it is
Clay Breaker is Winstone's garden grade gypsum, calcium sulphate dihydrate. Pure gypsum is 23.3% calcium and 18.6% sulphur; the bag carries Winstone's own typical analysis.
What it does
- Calcium from gypsum helps clay particles bind into crumbs, so heavy and compacted soil opens up, drains better and lets roots go deeper.
- Gypsum is a neutral salt. It does not move pH, which is why it can go on acid loving New Zealand natives and citrus as well as the vegetable garden and lawn.
- Calcium displaces sodium from clay, the standard treatment for sodic soils.
- It also supplies sulphur, which plants use for proteins, oils and flavour compounds.
How to use
- Suitable for vegetables, flowers, shrubs, citrus, fruit trees, large trees including acid loving New Zealand natives, and lawns.
- Apply at any time of year. For best results apply once in spring and again in autumn.
- New beds: dig into the soil before planting.
- Established lawns and trees: spread over the surface and water in well.
Watch out
- Gypsum does not raise pH. If the soil is acid and calcium is low, lime is the tool, not gypsum.
- Clay with plenty of calcium already will not change much. A soil test tells you which.
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Handling and storage
- Wear a mask to avoid inhaling particles and open the bag in a well ventilated area.
- Wear gloves and eye protection, and wash hands after use.
- Once opened, keep sealed and dry.
- If swallowed, or if the product gets into the eyes or irritates the skin, rinse the area well and call the National Poisons Centre on 0800 POISON (0800 764 766).
Shipping and returns
We ship nationwide across New Zealand. Orders are usually dispatched within 1 to 2 business days and rural delivery can take longer. Unopened products can be returned within 30 days.
