Plan the perfect garden with our interactive tool →

How to Soften Clay Soil

Italian soil image by apeschi from

Clay soil is soil with lots of tiny, dense particles. These particles are often closely-spaced and will not allow for good drainage. In early spring, clay soil is often soggy, waterlogged and slippery. Clay soil dries to a rock-hard texture in summer when water is no longer present in the soil. The best way to soften clay soil is to change its structure. A clay soil becomes less clay-like when the ratio of clay-particles to sand and loam particles is less than 50 percent.

Test your clay soil before attempting to soften it. The results of a soil test will tell you what percentage of your soil is clay. The test results will also make recommendations as to which amendments you should purchase, a schedule for amending your soil and how much of each amendment you should add to your clay soil.

Purchase soil amendments based on the test results. Common soil amendments for improving clay soil structure include organic material such as compost, peat moss and well-rotted manure. Additionally, you can aerate your soil by adding uncomposted kitchen scraps, straw and hay, and cotton husks. Gypsum can also help to break up clay soil, and lime will help to raise the pH of clay soil.

Break up the soil to a depth of 8 inches using a rototiller. Spread amendments over the soil in the amounts recommended by the test. In general, clay soil with less than 3 percent organic matter in it should be amended with 3 cubic yards of organic matter per 1,000 square feet. Amendments should cover clay soil as thick as 4 inches deep.

Mix the amendments with the soil by passing the rototiller over the soil again.


Many agriculture colleges maintain soil testing facilities in conjunction with their community and continuing education program. An extension agent at your local County Extension Service can give you instructions on the preferred method of collecting and packaging soil samples, as well as where to submit them and fees that apply.

Garden Guides