Everything You Need to Know About Thatch and How to Rid It From Your Lawn

Sharon Greenthal
Written by Sharon Greenthal
Reviewed by Tara Dudley
Updated July 9, 2021
Front lawn of two story house with cut grass and a large tree
Photo: Siri Stafford / The Image Bank / Getty Images

Keep thatch from becoming a big problem for your lawn by following these six tips for removal and maintenance

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Our lawns should be green, lush, and soft enough for bare feet on hot summer days. However, thatch can destroy the soil and quickly become a problem for even the most attentive gardener. Understand what thatch is, how to remove it, and maintain beautiful grass with this guide.

What Is Thatch?

Thatch naturally occurs when dead leaves, stems, and roots mix with living grass to form a dense intermingled layer that shows up between the soil and grass of your lawn. You can recognize thatch because it will be a dead patch that is dense and thick in an otherwise green lawn. 

A little thatch is beneficial to your grass, but a lot of thatch can quickly become problematic.

How Does Thatch Develop?

When there's more dead organic matter in the soil than the organic microorganisms in the ground are able to break down, thatch develops. These conditions can happen where there is too much water and insufficient drainage in the lawn or poor aeration. Watering your lawn too frequently or too many rainy days in a row contributes to the build-up of thatch.

How Do I Know Thatch Has Become a Problem?

You can measure a small piece of turf from your yard to see if thatch could be damaging to your lawn. Check the turf to see how much of the spongy layer is evident above the soil. If there is a half-inch to three-quarters of an inch of the porous part visible when you press it down, thatch is a problem, and you should remove it. 

A build-up of thatch can be a breeding ground for organisms that cause diseased grass and can become a welcoming environment for harmful insects. Pesticides can build up over a few years and bind to the thatch, keeping them from moving into the soil and reducing the earthworm population, which in turn prevents thatch breakdown. All of these things can cause sluggish growth and dying patches of grass.

Why Does My Lawn Need Aeration to Remove Thatch?

Lawn aeration is the process of poking holes in the soil with a piece of equipment to break up compacted soil. Aeration allows the ground to breathe and is necessary for thatch removal. There are local dethatching services that can take care of this process for you. 

“Aeration is also a good idea after a home exterior project such as siding, landscaping or other construction,” says Tara Dudley, owner of Plant Life Designs. “The compaction from equipment and crews is hard on the lawn and this is a great way to bring it back to a healthy state.”

The cost to aerate a lawn ranges from $0.10 to $0.35 per square foot. This price may seem expensive for those with large yards, but it will save money in the long run by keeping your grass healthy. You won't need to re-sod your lawn as often if your yard is free of thatch.

It’s best to do aeration before the weather gets too hot to get the maximum benefit from the process; fall is typically the best time for aeration. Aeration should occur once a year unless there is significant thatch build-up, and then twice a year is recommended. We also recommend overseeding the lawn after aerating.

green grassy yard with trees and sunlight streaming through leaves at golden hour
Photo: shunli zhao / Moment / Getty Images

How Do I Dethatch My Lawn?

Dethatching your lawn takes work, but it's essential to stay on top of thatch growth to prevent an even larger project in the future. If you have a local gardener who comes to your home regularly, you can also ask them to do the dethatching, though it will most likely be an added expense to your usual fee. 

However, if you want to dethatch your lawn yourself, follow these tips:

  • For small lawns, a dethatching rake will work fine.

  • If your property is large, you should rent a power dethatcher, which costs about $80 per day. The rental company will be able to give you more specific instructions on how to use it on your lawn.

  • Mow your lawn—but not too short.

  • Rake up the thatch, and then add seed to the bare parts.

How Do I Prevent Thatch from Developing?

After you've gone through the steps of dethatching, aerating, and seeding your lawn, you'll want to do everything you can to keep thatch from becoming a big problem again. Annual maintenance is essential, but keep an eye on any problem areas that may pop up on your lawn. 

If you don't have time for lawn maintenance, hire someone to mow your lawn for you. Professional lawn maintenance costs range from $50 to $220, depending on the size of your yard and where you live. 

Follow these lawn care guidelines to keep your grass healthy and your yard beautiful:

  • Never mow your lawn too short. Cutting one-third of the blade is plenty.

  • Keep your mower at 2 ½ inches in the spring and 3 inches in the summer.

  • Only use organic matter fertilizers on your lawn.

  • It's preferable to water less frequently and more deeply.

  • Avoid using pesticides on your grass. 

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