How to Condition Clay Soil

Clay soil has little organic matter and nutrients in it. To grow grass, flowers or vegetables, you'll need to condition the soil. Clay makes it difficult for roots to become established because there's little to no drainage and the roots of plants can't get enough oxygen. Conditioning clay soil will improve drainage and release nutrients into the soil that the plants need to thrive. You need to add organic matter to the soil each year to get the most benefit from the conditioned clay soil. The warmer the soil, the more organic matter that is consumed.

Till or spade

Rotted manure or leaves

Compost

Peat moss

Ammonium sulfate fertilizer

Lime

Phosphorous

Contact the Cooperative Extension at a local university to have the soil tested to find out how much organic matter and nutrients there are in the soil.

Till the soil after the last frost in the spring to loosen it and make planting easier. Till the soil to a depth of at least 10 inches.

Add 3 to 4 inches of rotted manure, leaves, compost or peat moss to the soil. Till it into the soil a little at a time to a depth of 6 inches.

Till lime and phosphorous down into the soil as needed, depending on the results of the soil testing.

Add ammonium sulfate fertilizer to the soil during tilling to give the plants nutrients until the organic matter can break down in the soil.

Soil testing will help you calculate how much organic matter and other nutrients you'll need to add to condition the clay.

Buy a soil testing kit, but if you're not sure what you need, ask the Cooperative Extension for advice.

Don't till clay soil when it's wet because it will compact the clay and destroy the structure of the soil.

Don't use sand to condition clay soil. The clay will become as hard as rock.