How to Rid that Lawn of Thatch!

You know that brown patchy debris in a lawn that accumulates on top of the soil but below the grass line? That's thatch.

Thatch consist of grass clippings, grass stems, roots, and other debris that either decomposes or accumulates on a lawn over time.

A few reasons thatch can occur are

1) A lawn has never been aerated

2) Cutting high grass frequently and leaving the clippings on a lawn.

Thatch is not always a bad thing as it can hold moisture to protect the lawn from extreme heat and lack of water.

Questions to be asked before removing thatch(dethatching)

1) Is there enough thatch on the lawn to justify dethatching?

2) If so, what process should I use to dethatch the lawn?

Lawn business owners and homeowners need to measure the amount of thatch in a lawn to determine if dethatching needs to be done. I prefer to take a pencil and stick it in the thatch until it touches the ground.Mark the pencil with your fingernail where the thatch comes up to.

After doing this a few times you will be able to eye it and know whether or not to dethatch. The first couple of times you can measure with a ruler.

As a guide, anything over 1/2 inch should be dethatched as this prevents adequete nutrients, air, and water from reaching the soil. Excessive thatch can also encourage pests and lawn diseases.

Dethatching can be done in 3 ways depending on the size of the lawn and the amount of thatch accumulated.

1) Aeration- For lawns that have less than an inch of thatch. This is done with an aerator. Always use an aerator that pulls plugs from the ground as opposed to the ones that poke holes.

2) Rake the lawn manually- using a leaf rake, garden rake, or thatching rake. Raking is fine for small to medium size lawns with thatch less than 1 inch. Raking does take some time, but less stressful on the lawn than a Power Rake.

3) Power Rake- Also called a Power Dethatcher. Use this when there is more than 1 inch of thatch on the lawn. Power Rakes are a stout piece of equipment that uses an engine like a lawn mower to drive vertical blades or tines to cut the surface of the soil. These blades or tines can be adjusted to certain depths.

You can rent either a power rake or an aerator from Home Depot or another equipment rental store in your area.

If you decide to dethatch using a power rake mow the lawn to about half of its regular mowing height.

The blades of the power rake should be adjusted to cut about 1/2 inch into the soil to remove thatch. Always go over the yard twice and change direction of your paths. For example, (long ways and short ways) or (diagonal one way and diagonal the other way).

After dethatching, rake up all the debris and thatch.

If you would like to fertilize or reseed the lawn, this is a good time as roots are exposed.

Water when you are finished dethatching.

Since some power dethatching can make a yard look bad, remember to dethatch when a lawn can recover the best such as right before the prime growing seasons. Different types of grasses have best and worst times to dethatch because the growing seasons vary.

Having a healthy lawn can can definitely improve the look of the landscape and the curb appeal.

If you need any questions answered, please ask them at so the other members can benefit.

I'm here to help,

Kevin Whiteside

Kevin Whiteside is the owner and editor of Monthly, an online newsletter for lawn and landscape professionals. Get a FREE subscription here

He is also the author of "Turn High Grass Into Cold Cash- How to Start the Ultimate Lawn Service"

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