Lawn Repair

AMERICAN LAWN GUIDE

simple lawn care tips for greener healthier backyard lawns
Lawn Thatch

Thatch is the brown layer which lay at the base of the lawn, and above the soil. Thatch is a very generic term and the word does not describe a single part of the lawn. Instead, the word thatch actually describes a range of different organic matter which can be both dead and alive and which exists below the green leaf of the turf.

Thatch can be made up of old leaf litter, clippings from lawn mowing, and in the case of Warm Season lawns, thatch is most commonly associated with old stolons (above ground runners) which have been overgrown by new lawn growth. These runners can be both dead or alive, and can still be playing an important role in supporting the turf.

The Purpose Of Thatch and Why Thatch Can Be A Probelm

All lawns will have some degree of thatching, if a lawn didn't have thatch it would only be because the grass is bare and dying.

The purpose of thatch is a very important one, it blankets the soil and protects it from drying out too much in the heat, which conserves water and also protects the roots of the lawn. It's like nature's little mulch layer for our lawns.

Thatch becomes a problem when it continue to increase in thickness which will occur on all lawn types that are being well maintained. As the thatch layer increases more and more water is prevented from reaching the soil, instead it sits inside the thatch and slowly evaporates away. All this moisture inside the thatch layer is also the perfect environment for lawn diseases and lawn pests like army worm to thrive and multiply. If that wasn't bad enough we also have to deal with one more problem, which is lawn mowing.

Mowing through thatch often leaves the lawn looking scalped and brown, which can be extremely damaging to turf, more so is the crowns of the lawn have raised up and we cut into them - with the end result being dead lawn wherever this has happened. If we try and raise the lawn mowing height, the problem only gets worse as the thatch layer continues to get thicker at a faster rate.

Controlling Thatch

The only real way to control thatch is to remove it, and there are 3 ways to remove thatch.

Lawn Mowing
This method can only be used for Warm Season grass types, with Zoysia and Bermuda getting the best results. In the cooler times of the growing season such as early Spring or early Fall, we simply cut back the lawn to a very low level and remove most of the thatch in the process. This will create a lot of waste material, and the lawn should be lightly fertilized and water maintained in the following 2 weeks. The lawn will look brown and horrible for a while but it will regenerate from it's runners.

Warning: the lawn mowing method should never be used on Cool Season grasses such as Bluegrass, Ryegrass or Fescues.

De-Thatching
This method uses a special de-thatching machine which will severely cut back all the dead thatch similar to the lawn mowing method - the difference is that this process was specifically designed for the purpose of de-thatching and to give the greatest results. It's a dirty jobs and creates a lot of waste. It's often something best left to professionals. De-thatching is sometimes known as Vertimowing.

Lawn Core Aeration
Lawn core aeration uses a different type of machine which goes over the lawn and removes plugs of soil, grass and thatch. The process is very good at thatch reduction with high safety levels for the lawn from being damaged, this is more so with Cool Season grasses. Lawn core aeration is also a means of aerating the soil which is highly beneficial for all lawns to reduce compaction and increase lawn health. After the lawn aeration is completed, the lawn is simply mowed as normal with a rotary mower and all the plugs are removed.

It's always a great idea to feed the lawn and soil directly after lawn aeration, a light feeding with a quality fertilizer and some Wetting Agents will do wonders for the lawn if applied now.