Ideal Soil Composition for Lawn Grass

Soil Composition

• According to the University of Illinois Extension, soils are composed of varying amounts of three different types of soil particles: sand, silt and clay. Sand particles are large, coarse and give the soil a rough texture. Silt particles are smaller than sand, larger than clay and give the soil a smooth, powdery texture. Clay particles are the smallest of the three and make soil feel sticky when its wet.

Composition and Lawns

• Soil and plant specialists at Washington State University report that soils composed of 60 to 70 percent sand and a 30 to 40 percent mixture of silt and clay are ideal for growing grass. Soils containing more sand than specified dry out quickly and are nutritionally deficient. Those containing too much clay inhibit air and water flow.

Improving Soil Composition

• According to Washington State University experts, amending soil to support lawn growth is possible with most soils. They recommend working approximately 2 inches of organic matter, such as compost, manure or sawdust, into 6 to 8 inches of soil to improve its structure.