Clay soil lacks the porosity to allow plants to grow well in it. By adding the right materials to it, clay soil can better sustain plant growth.
Step 1: Add organic matter Mix organic matter such as commercial or homemade compost into the soil using a garden spade. Anything derived from plant or animal matter will help improve the soil structure.
TIP: Do not add sand, which will not mix with clay.
Step 2: Add iron sulfate Mix in iron sulfate as a source of iron. While there is iron in clay, it is very hard for plants to extract it from clay.
Step 3: Add phosphate Mix in a phosphate supplement containing gypsum. Gypsum loosens the clay’s attraction to itself.
FACT: Mulches are laid on top the surface of the soil, but soil amendments are mixed into it.