How to Improve the Tilth of Clay Soil


Clay soil presents a host of problems for the gardener. Clay compacts easily, cutting off oxygen to plants' roots. It also has poor drainage, holding water for long periods. Clay soil tends to be saltier than other soils as well. Managing clay soil is important to your garden's success. The tilth of the soil, its physical condition as it relates to supporting plant life, is an aspect that merits close attention and, with clay soil, a lot of work. Clay soil may take years to fully amend.

Step 1

Dig into the soil to a depth of 10 inches with a shovel. As you dig, turn the soil over and crush it with the shovel or gardening fork. If the soil is moist, wait until it is dry to work on it, as working wet clay soil causes it to compact.

Step 2

Add a 4-inch layer of shredded bark and a 4-inch layer of compost to the existing soil. Mix the amendments into the top 4 inches of soil. Rake the area until it is level.

Step 3

Spread a 4-inch layer of wood chips over the top of the soil. Do not mix the chips into the soil, but allow them to sit over the winter. They will break down and help aerate the soil.

Step 4

Till the soil in the spring, as soon as the ground has thawed enough to work and the soil is dry. Dig the wood chips into the soil to a depth of 10 inches.

Step 5

Spread a 3-inch layer of compost over the area and mix it in to a depth of 6 inches. The tilth of the soil should be amended enough to allow you to plant.

Step 6

Spread a 4-inch layer of wood chips over the area again, each winter, and allow them to overwinter on top of the soil.

Things You'll Need

  • Shovel
  • Gardening fork
  • Bark
  • Compost
  • Wood chips
  • Rototiller


  • Colorado State University Extension: Managing Soil Tilth
  • University of California at Davis:Clay Garden Soils Require Special Care

Who Can Help

  • Washington State University: The Myth of Soil Amendments
Keywords: improve clay soil, manage soil tilth, clay soil tilth

About this Author

Victoria Hunter, a former broadcaster and real estate agent, has provided audio and written services to both small businesses and large corporations, worldwide. Hunter is a freelance writer specializing in the real estate industry. She devotes her spare time to her other passions: gardening and cooking. Hunter holds a Bachelor of Arts in English/creative writing.