Soil can be friend or foe to your lawn, either encouraging or hampering grass health. You can do everything right at the surface—watering, mowing, fertilizing—but the soil underneath could be thwarting your efforts. Fall is a good time to learn more about your yard’s soil and how it may be affecting your lawn’s health.
Three basic textures combine to create soil type:
Clay: fine, sticky particles that easily bind together
Silt: medium, floury particles that loosely bind together
- Sand: coarse, gritty particles that will not hold together
The unique combination of these textures in your yard makes up your soil type.
Simple Soil Texture Test
For a simple test, dig down three or four inches below the grass. Take a handful of soil, and if it’s dry, dampen it slightly. Now try to roll it into a ball.
- If you can easily roll it into a ball or a ribbon, your soil type is clay.
- If the soil remains loose and won’t bind into a ball, then your soil is sandy.
- Loamy soil is a balanced soil of all three textures that holds together loosely, but won’t form a compact ball.
Of course soil types span a wide spectrum, and your soil likely falls somewhere in between these three basic types, but let’s take a look at the general characteristics.
- Clay soil tends to be heavier and prone to compacting, restricting water and airflow.
- Loamy soil is usually dark and crumbly. It allows airflow and holds beneficial water but still allows for drainage.
- Sandy soil lets water and nutrients pass through too quickly, making them less available to plants
Grass by Soil Type
Count yourself lucky if your lawn is growing in loamy soil. Loam is the most favorable soil type for growing grass and other plants. It holds just enough water and nutrients without compacting or draining too quickly. Unfortunately, balanced loamy soil is not prevalent in our area.
Sandy soil, presenting as loamy sand or sandy loam, covers much of Georgia and the surrounding area. The biggest challenge for grass in sandy soils lies in getting enough water and nutrients to the roots before it all drains away.
To amend sandy soil, top dress your lawn with compost in late spring for warm season grass, like Bermuda or zoysia, and in early spring and fall for cool season grass like fescue. The organic material will add nutrients and improve the soil’s ability to hold moisture.
Clay soil can present multiple challenges for grass roots. It tends to stay too soggy during wet weather, promoting root rot, and it gets rock hard during dry weather, discouraging root growth. Clay’s tendency to compact also keeps air, water and nutrients from circulating properly.
Top dress grass in clay soil each spring with compost, providing nutrients in addition to improving soil texture. Aerating with a core (not tine) aerator each spring also benefits lawns in clay soil, creating space for air and water to flow.