Lawn Thatch 101

Thatch is an unseen component of your lawn that can make the grass healthy in small amounts but will suffocate your lawn if it develops out of control.

What Is Thatch?

Thatch is naturally produced in a grass lawn. It can be comprised of grass clippings as well as grass blades that have naturally died. There is also living material in the thatch, including the stolons and surface roots of the grass plants. There may also be dead leaves and small twigs matted into the thatch.

The thatch materials form into a mat, often held together by the surface roots in the layer. The mat collects right on top of the soil, around the base of the grass plants. It will form a mat that blankets the soil, similar to a mulch layer.

Thatch Problems

A thin layer of thatch is actually desirable because it acts as a mulch for your lawn. The issue is when the thatch becomes too thick. Heavy layers of matted thatch prevent moisture and nutrients from soaking into the soil. New grass blades may also have problems penetrating the thatch to grow up to the sun

Over time, bald or thin areas may develop in the lawn where the grass is being choked out by heavy thatch. In shaded areas, the ground may also feel spongy as trapped moisture in the thatch is unable to dry out, leading to grass rot from suffocation. Even if the grass continues to grow, it may be week and yellowing due to the lack of fertilizers soaking into the soil. Thatch problems can be a problem anywhere on the lawn.

Removal and Prevention

Thatch should be removed any time it develops a layer that is more than 1/4 to 1/2 inch thick. A lawn can be dethatched manually with a special rake designed to pull up the thatch but not the grass, but this is best reserved for small areas. For larger areas, a power rake is a mechanized version of the tool that completes the job much quicker. Once removed, the collected thatch is raked off the lawn surface for disposal or composting.

You can avoid heavy thatch buildup by either collecting grass clippings or use a mulching mower that chops them finely for quick decomposition. Further, avoid over-fertilizing, as overly rapid growth can lead to thatch. Finally, regular mowing and yearly aerating will also minimize thatch development.

Contact a lawn care service like All-Green Inc if you are concerned about the thatch layer on your lawn.