Add rock minerals to soil
If you’re an organic gardener, you’re probably adding compost, manures and organic fertilisers to your soil on a regular basis. While these can provide a good supply of macro nutrients such as nitrogen, they often lack other elements that plants need, including potassium, magnesium, silicon and iron. Rock minerals restore essential minerals to soil while stimulating microbial activity. Various products are made from a blend of rocks rich in minerals, including basalt, greenstone, lignite, gypsum, rock phosphate and granite. These are ground to a fine dust, then pelletised to make it easy to spread. Add a generous handful per square metre when preparing soil. The minerals are released slowly, providing nutrients over an extended period.