Brown thatch layer between soil and lawn leaf

What Is Lawn Thatch

Thatch is a layer of organic matter that lies underneath the top green layer of the lawn.

In Warm Season Lawns, thatch is comprised of living and dead runners (stolons), as well as other build up of organic material such as lawn clippings, and other organic plant matter which is in the process of breaking down.

Thatch in Cool Season Lawns is an assortment of dead or dying leaf matter, lawn clippings, and other organic material.

Importance Of Thatch In Lawn Care

A layer of thatch is vitally important to the ongoing health of a quality lawn. It provides insulation to the lawn's root system, preventing evaporation of water and any drying out or dying of the lawn's roots.

The thatch is what provides the softness to lawns under foot, that makes them so functional as play or relaxation areas.

And a healthy thatch layer is part of the lawn that helps to prevent damage occurring by providing a thick knitted layer of runners, or thick tillering that work together to create a cushioning protection for the lawn.

When Thatch Problems Occur

Even with the best lawn care, over time, thatch can build up to excessive levels, this can be for many reasons, either by natural course, or through being sped up by bad lawn practices such as infrequent mowing.

Once excessive thatch is present, it must be dealt with, otherwise many problems will start occurring. Mowing will become more difficult, and each mowing will constantly cut back into the thatch layer, removing all the green leaf, and revealing the brown thatch layer.

• Lawns become ugly from the constant straw like undergrowth being revealed.
• With the removal of all the green leaf, Photosynthesis stops, and the lawn begins to suffer and starve from lack of food.
• With the lack of food, lawns cannot quickly recover from it's damaged state
• It's a continuing cycle

Extreme Lawn Thatching

The brown thatch layer between soil and leaf

Lawns such as Buffalo can be at risk of extreme thatching, where the lawn continues to grow higher and higher above the ground. At the base of the thick layer is the original lawn, long since dead, and the entire lawn is now comprised of a mixture of living and dead stolons and roots.

Eventually, as the lawn continues to grow and regenerate, new roots will no longer reach into the soil, they will stay in the underlying dead lawn matter, at high risk of dehydration, starvation from lack of nutrients, and death.

Repairing Lawn Thatch

The only remedy to a severely thatched up lawn is to remove the thatch.

For Cool Season Grasses, this is best achieved by carefully reducing the mowing height over a few cuts with a Rotary Mower to remove any loose material. Then returning heights back to a healthy and normal level.

In most cases, the very best way to remove thatch in Warm Season Grasses is to Vertimow. Remembering that vertimowing can only be carried out on Warm Season Grasses that have stolons (runners).

Vertimowing Information

For more information, please see our Vertimowing Article.

Lawn Care Tip
Vertimowing is also known as de-thatching, and scarifying, and is essential in the lawn care regimes of all warm season lawns.