Thatch

Thatch is a dense layer of decomposing and dead roots and underground stems and leaves which accumulate between the green visible grass blades and the soil surface.
An actively growing lawn accumulates thatch as a natural occurrence.

However, when the production of this layer exceeds the ability of the soil's organisms to break it down, a build-up occurs.
If the lawn is mowed at the proper height and frequency, it is not necessary to collect lawn clippings when mowing. The clippings contribute only a minor amount to thatch accumulation, since they decompose rapidly in contrast to the tougher roots and underground shoots.

Thatch Impact on Lawns:
A small amount of thatch (1/2" or less) is actually beneficial for the lawn, since it promotes turf resiliency and provides nutrients as it decomposes. However, when the thatch layer exceeds 1/2", it becomes undesirable. This amount of thatch increases turfgrass diseases and reduces the lawn's tolerance to drought, heat and cold. A thatch build-up will also minimize the movement of air, water and Pro Care treatments through the turf into the soil. Deterioration of the turf will occur if thatch growth is allowed to go unchecked and turfgrass plants begin to grow in thatch rather than soil.

Signs and Symptoms:
The thatch layer should be measured if large areas or patches in the lawn appear to be dried out after adequate watering, if scalping injury occurs at proper mowing height, or if the lawn does not respond well to Pro Care treatments. The dark, spongy layer between the soil surface and green vegetation may be measured by cutting a pie-shaped wedge in the lawn. A thatch accumulation of 1/2" or more will present potential problems.

Pro-Care Practices for Control:
Core aeration removes plugs of thatch and soil and deposits them on the lawn surface to deteriorate. As the plugs sift down into the lawn surface, they deposit soil into the thatch. This will increase the thatch degradation as a result of the microorganism activity in the soil. The lawn will also experience other benefits of core aeration, including watering and air infiltration and reduced soil compaction. Core aeration is included in Pro Care's program.

Cultural Practices for Control:
Gasoline-powered vertical rakes or "dethatchers" are available at rental stores and garden centers for use in dethatching. This process is time-consuming and creates a vast amount of debris to be disposed. Improperly performed, this process may be very damaging to the lawn. The blades must be set through the thatch and must penetrate into the soil from 1/4" to 1/2". The best time for dethatching is in early fall while there is enough season remaining for the lawn to recover. Overseeding at this time with a good quality blend is also recommended. Please contact Pro Care so that your Pro Care treatments may be coordinated with this dethatching operation.
Topdressing the lawn manually with 1/8" of soil, which matches the existing type, will also deposit soil into the thatch layer. This practice may or may not be practical for the homeowner.

The Pro-Care staff is always ready to assist you with your lawn. Please call if we may provide any information to enhance your lawn's health or appearance.