What is Thatch?

What is thatch?

Thatch is a layer of living and dead stems, roots, leaves, and other organic matter which accumulates between the soil and turf. Thatch is a natural component of the growing turf and is beneficial as long as it doesn’t get too thick.

Excessive thatch that is more than ½ inch to ¾ inch can prevent necessary water, air and fertilizer movement to the roots. Poor thatch can reduce drought resistance and allow lawns to dry out quicker than normal. Once excessive thatch dries out, it can be very difficult to introduce moisture. If this happens, along with high humidity, there will be an increase in disease activity.

So how does thatch develop? Some of the major contributions to thatch are practices that reduce the population of organisms that help reduce thatch. Earthworms play a good role in decomposing thatch, along with other microbial activity. Core Aeration and good pH levels that range 6.5 to 7 allow for healthy microbial activity. Balanced fertilizers keep lawns from growing too fast and do not promote disease activity.

What is Thatch?

So how does thatch develop? Some of the major contributions to thatch are practices that reduce the population of organisms that help reduce thatch. Earthworms play a good role in decomposing thatch, along with other microbial activity. Core Aeration and good pH levels that range 6.5 to 7 allow for healthy microbial activity. Balanced fertilizers keep lawns from growing too fast and do not promote disease activity.

How can you tell if you have excessive thatch? We use a soil probe to pull a core in which you can see the thatch build up. Homeowners can cut a small area, several inches deep. The sponge area between the soil and turf is the thatch layer. If thatch is ½ inch when compressed you should consider dethatching the lawn or doing a core aeration. StayGreen recommends doing this in the fall.

Learn More about StayGreen Lawn Service Programs >

To learn more about managing you lawn grass clippings,
visit the University of Minnesota Extension Sustainable Urban Landscape Series >

* Thatch diagram courtesy of University of Minnesota Extension. Photo by: Bob Mugaas, U of M  –  All rights reserved.
2018-05-30T18:35:48+00:00