Thatch is a layer of dead stems, roots, and shoots that build up between your grass blades and the topsoil.
All grass has some thatch, and up to half an inch is actually beneficial to your lawn care. It provides a layer of insulation that protects the ground against drought and extreme temperatures.
However, a thick layer of thatch causes several problems, which will be further explored in a moment.
Why doesn’t thatch just thin out when the grass is mowed? Even when some of the thatch is sliced up by the mower blades, it simply does not break down as quickly as grass blades. The material that is composed of doesn’t break down as quickly as the blades themselves.
Rather than decomposing and nourishing your soil, the thatch buildup just gets thicker over time. This eventually creates a dense barrier that’s detrimental to the health of your grass’s roots and blades.
Problems Caused by Thatch Buildup
Excessive thatch creates an ideal environment for various lawn pests to propagate. Too many grub worms, for instance, can harm your soil. And no matter what lawn pest you’re dealing with, the more of them there are, the more difficult they are to eradicate.
Additionally, thatch is adjacent to your grass’s root system, and is often still connected to it at various parts. It dries out easily, which can further lead to the root system drying up as well.
Needless to say, this is bad news for your grass bed and topsoil. Saturated thatch from excessive moisture is also detrimental to your grass. It allows harmful microbes to flourish, eventually leading to root rot. In the presence of root rot, a mower’s blades can accidentally “scalp” patches of your lawn when they catch and tug up a patch of built-up thatch.
Last, thatch itself- whether wet or dry- will slowly starve out your topsoil if it’s had a chance to accumulate to an unhealthy height and density. It acts as a barrier against the effective absorption of water, sunlight, and vital nutrients.
Some experts recommend investing in turf grass blends that include tall fescue or rye grass.
These varieties tend to produce less thatch in general, which reduces the amount of care and maintenance your lawn needs in regards to thatch removal.
Acidic soil, as well as excessive fertilizing practices, can contribute to thatch buildup. Be sure you monitor your fertilization schedule and don’t overdo it. If you don’t have a soil pH test kit,
you can find one at a garden store or ask a lawn care company to help out.
Aerate in the fall, if and when necessary, to promote healthy soil. Doing so can help reduce thatch buildup. If you notice an overgrowth of thatch- that is, over half an inch beneath your grass blades- dethatch your lawn in the spring or fall, during milder weather.