Bulk - Gypsum

Gypsum is the standard fix for Adelaide's heavy clay soils. It works chemically rather than physically — calcium ions displace the sodium that makes clay particles disperse and set like concrete, so the clay flocculates into crumbs that water and roots can move through.

What it's used for

• Breaking up sodic clay before planting garden beds or laying turf
• Improving drainage in areas that pond after rain
• Adding calcium to soil without raising pH — unlike lime
• Pasture and broadacre soil conditioning

How much to apply

For garden beds and lawns, spread at roughly 1kg per square metre (1 tonne per 1,000m²) and water in well. Severely compacted clay can take double that, applied over two seasons.

Yard tip: Gypsum only helps if your clay is sodic. Drop a dry crumb of your soil into a glass of clean water — if the water goes cloudy within a few hours, gypsum will work. If it stays clear, you need organic matter instead.

Delivery

Priced per tonne, delivered across metropolitan Adelaide, GST included. We place the load where you actually need it rather than dropping it at the kerb — that's the difference between a morning of barrowing and none. Order online, or call the yard on (08) 8443 9533 if you'd like a hand working out quantities.