Soil texture is defined as the particle size of individual soil particles. The largest particles of soil are present in coarse, sandy soil. The smallest particles are in clay soil. Most soil is a blend of these two soil types. Soil that contains more clay particles will not drain well. Clay soil is slippery when it is wet and rock-hard when it dries. Many garden plants require good drainage, and do not adapt well to clay soil. Organic soil amendments can help to improve the structure of clay soil.
Have your soil tested before you plan your garden to determine what soil amendments you should incorporate. The USDA maintains soil testing facilities in most states in conjunction with the state land grant college's community and continuing educational program. By contacting an agent with your state college's county extension service agency, you will be directed in the proffered method for collecting soil samples, how to package them, fees that apply and where to send samples.
Purchase amendments based on the recommendations in step 1. Incorporating rich organic material such as compost will help to improve the nutrient structure and drainage in clay soil. Sand and gypsum will also help clay soil to improve drainage. You may also need to add sulfur to your clay soil to lower the pH. Clay soils are usually alkaline with a pH that ranges from 7 to 8.5. Most plants thrive in a soil with a pH of 6.
Break up soil in the fall with a rototiller before amending it in the spring. Fall-tilled clay soil will be loose and fluffy in spring, which makes it easier to amend.
Break up your soil to a depth of 6 inches with a rototiller. Spread 4 inches of soil amendments over the top of the soil. Mix these amendments into the soil by passing the rototiller over the soil again.
Smooth out your garden's soil with a rake and break up any clods before planting in your soil. Plant garden plants directly into amended soil.