How To Dethatch Your Lawn With A Mower Attachment

Written by Mike Futia

Updated January 12, 2023

In this article, we’ll help you get your yard looking even better by teaching you how to dethatch your lawn with a mower attachment.

How To Dethatch A Lawn With A Mower Attachment

In this section, we’ll teach you step-by-step exactly how to dethatch with a mower attachment:

Check The Lawn Needs Dethatching

A thin layer of thatch (up to ¼-inch) is actually beneficial to the lawn. Dethatching when there is only this much thatch present actually causes harm to your lawn. (See the pros and cons of dethatching).

A lawn that needs dethatching can often feel spongy when walked on, or be difficult to mow without causing visual distress.

lawn sample

Checking for thatch

To confirm that your lawn needs dethatching, remove a small section of your lawn surface first with an appropriate implement such as a spade. This removed section does not need to be large– just big enough to see, as in the picture above.

Use a ruler or similar instrument to check the depth of the thatch layer, which is present just above the soil.

If the depth of thatch is greater than ¼-inch, you might want to consider dethatching your lawn.

At this point, any damage to the lawn is unlikely to be severe, and there is some debate as to whether dethatching is necessary before thatch depth has reached ½ an inch.

However, if your thatch depth is larger than ½ an inch, your lawn definitely needs to be dethatched as soon as possible.

Trim The Grass

In order to get access to the thatch and remove it, you’ll need to make sure your lawn is relatively short.

Trim your lawn a little lower than you typically would to ensure that the thatch is exposed.

Remove The Cutting Blades

Mower blade

You’ll now need to remove the regular mower blades before you attach the dethatching apparatus.

The exact process depends on which model of lawn mower you own, and you should consult your manual before performing this part of the process.

However, some general steps still apply. For instance, you’ll need to prop your mower up to allow access to the blades. Tilt it towards the handle and prop it up at the other end.

Before doing anything involving a mower’s blade, disconnect the source of ignition. The last thing we want to be doing is walking out of here with less fingers than we came in with.

If you have a petrol mower, disconnect the spark plug. If you have an electric mower, disconnect the power cord and/or remove the battery.

Attaching The Mower Dethatching Blades

Dethatching blade attachment

The dethatching blades should be fairly similar in attachment to the regular blades that you’ve just removed.

Again, detailed instructions around reattaching the blades depend on your lawn mower and the blade that you’re using, so you should consult the manuals and instructions for your product of choice first.

However, one absolute is that you need to have the protrusions from the blade (typically spring-like assemblies with a loose end) facing down, towards the lawn. These are what will be engaged in the dethatching process.


Replace the power source of the mower and make sure that the blade rotates properly and freely.  If it doesn’t, review the attachment and make sure that everything has been done correctly.

Raise the deck of your lawn mower as high as it goes.


In a small area of your lawn, run the lawnmower and observe whether it brings any thatch to the surface of the lawn.

Adjusting And Dethatching

After doing a brief test, examine the area that you have attempted to dethatch.

If you’re not seeing any thatch brought to the surface, you’ll need to lower the deck and try again. 

If you are seeing lines formed in the soil by the prongs of the dethatching blade, you’ll want to raise the deck.

Repeat the testing step until you are achieving the desired result. 

You’ll know it’s successful when thatch is being brought to the surface, but no soil damage is taking place. Then, finish dethatching the entire lawn.

Fertilize And Water The Lawn


Adding fertilizer

After dethatching, make sure you fertilize and water the lawn. 

Removing the thatch means that you can access the soil layer directly, so you’ll be able to provide a lot of nutrients and hydration to your soil immediately after dethatching.

This process is also important to restore any grass that may have been damaged during the dethatching process.

If your lawn still looks bad after dethatching, you'll want to troubleshoot the potential causes.

What Is Thatch?

Thatch is a buildup of lawn clippings, broken stems, dead grass, and other garden rubbish that can build up in a layer above the soil of your lawn.

Thatch can actually be beneficial to your lawn when there is only a small amount of it (the rule of thumb is that it can be up to a ¼-inch deep).

At this level, the thatch will feed the soil by decomposing, as well as prevent excessive soil compaction by providing a cushion between any pressure and the soil itself.

However, when it gets too deep, it can overstress living grass and prevent water entering the soil– leading to a decrease in grass growth and overall lawn health.

Do Mower Dethatching Blades Work?

Mower dethatching blades, while not as efficient as specialized dethatching equipment, can and will do a decent job job.  

You may need to be more patient with them than you would with a specialized dethatcher, however.

How Often Should You Dethatch A Lawn? 

Overly dethatching a lawn can be harmful to the soil health, so you shouldn’t dethatch too often.

Exactly how often you should dethatch your lawn depends on what kind of grass you have, and how quickly thatch accumulates on your lawn.

It might be helpful to do some regular measurements over the course of several months to determine how fast thatch builds up on your lawn, as doing so will help you answer this question in greater detail.

However, a good rule of thumb is to dethatch a lawn at least once a year, and increase this frequency if your lawn shows signs of over-accumulation of thatch.

Other Ways Of Dethatching A Lawn

You can also use specialized dethatching equipment to dethatch your lawn. Power rakes, vertical mowers, and dethatchers are all devices that will help dethatch your lawn.

However, it’s less likely that you just happen to have these devices on hand. Additionally, renting them can be expensive, which means that attaching a dethatching blade to your lawnmower is likely to be easier and cheaper.

These standalone devices are typically more efficient however, as they are designed specifically for the task.

Liquid dethatcher is another option, but it's not very effective.

Frequently Asked Questions

Is Dethatching Just Raking?

Yes, and no. The process of dethatching can be done using a special kind of rake called a power rake, or with a regular rake at a pinch.

However, simply raking a lawn normally will not produce a large dethatching effect, and normally a specialized process is needed to fully dethatch a lawn.

How Do You Make A Dethatcher Blade?

You can take a regular mower blade and drill holes in each side, through which you can thread some grass trimmer line or similar material in order to provide dethatching “spikes”. 

However, it’s often easier to buy a dethatcher blade outright. If you’re curious about making your own, check out this video.

Is It Better To Dethatch Your Lawn Wet Or Dry?

Neither. You should aim to dethatch when your lawn is moist. 

If you dethatch when it's too wet, you risk getting the thatch tangled in the grass and causing damage to the lawn. Too dry, and things also won’t work particularly well.

How Low should you Mow before Dethatching?

Mow your lawn a little lower than you normally would. 

Some will suggest mowing it to half height, but depending on when your latest mow was and how fast your grass grows, that may be unnecessary.

What Happens if you don't Dethatch?

If you don’t dethatch your lawn, the layer of thatch will build up to unhealthy levels. 

This can constrict your glass blades, prevent moisture from reaching the soil, and compress the soil itself– causing damage to your lawn’s root system.

In other words, your lawn’s health will decline if you don’t dethatch.

What does a Lawn that Needs Dethatching Look Like?


A lawn that needs dethatching might have an obvious buildup of grass clippings when you look at it from a moderate distance.


It may also look scruffy or untidy even when you have just mown it, due to the large amount of garden debris underneath the surface of the grass blades.

Final Thoughts

Dethatching your lawn is important for its overall health, and you should aim to do it relatively frequently (at least once a year).  Too much thatch can crush and constrict your grass.

Using a mower attachment to dethatch your lawn can produce results relatively quickly and cheaply when compared to a specialized dethatcher, even though it may be less efficient. 

Just follow the steps outlined in this guide, and your lawn will be dethatched to perfection before you know it.

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Mike Futia

My name is Mike, and I'm the owner and founder of My lawn care advice has been featured on Family Handyman, Home & Gardens, Gardening Etc., and Apartment Therapy. I love nothing more than helping my readers achieve their dream lawns. That's why I started, where I share all of my best tips and tricks for keeping a lawn healthy and well-maintained. You can read more about our mission on our About Page.

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