Clay soil is not optimal for growing plants due to the heaviness of the soil. When soil is too heavy, it lacks essential nutrients as well as proper drainage capabilities. To improve clay soil, you must loosen it by adding materials such as manure, compost or bark mulch. As you loosen the soil with these soil amendments, you will also be improving the quality of the clay soil and making it more fit for sustaining plants.
Use the rototiller or the garden spade to break up the top 6 to 8 inches of soil.
Add 2 inches of peat moss and 4 inches of aged bark mulch to the top of the soil.
Work the peat moss and bark mulch into the soil with the rototiller or garden spade until it is completely incorporated.
Rake the soil smooth to finish improving the clay soil.