How Thatch Develops

 Your lawn is home to more than just your grass and ornamental plants. Some of your lawn’s residents are detrimental, but others are beneficial. Some of these beneficial residents are organisms like earthworms and microbes that decompose organic material. Since thatch is made of organic material, it develops when your lawn produces more organic material than the organisms in the soil can decompose.

Thatch development is a natural process, but the speed at which it accumulates is what homeowners can influence. Bad lawn care practices and lawn management can speed up the process of thatch accumulation. Here are some ways you might be contributing to thatch development:

• Excessive fungicide and pesticide use. Decomposers are living things that break down organic material. Using too many fungicides and insecticides can kill earthworms, microorganisms, and other decomposers, leading to more thatch.

• Bad fertilization practices. Typically, bad fertilization technique results in too much nitrogen being introduced to your lawn, which can invite disease. This also promotes fast and vigorous lawn growth, which means it’s producing more organic material that can become part of the thatch layer.

• Highly acidic soils. While grass typically prefers more acidic over alkaline soils, too low of a soil pH can kill beneficial organisms, resulting in thatch buildup.

• Soil compaction. Compacted soil isn’t an ideal environment for grass and microorganisms alike.

• Improper irrigation. Watering your lawn too much will discourage deep root growth. Roots can also contribute to thatch buildup.

• Bad mowing practices. If you don’t mow your lawn frequently and let it grow tall, you’re more likely to take off more than ⅓ of your turf’s leaf blades. You might get more of the stem, which breaks down slower than the leaves.