Why, When, and How to Dethatch Your Lawn

Boulder, CO Lawn Maintenance Companies

Here at GSC, we’re serious about quality lawn care. We know there are many factors that go into growing and maintaining a beautiful lawn, from proper watering and pest control to choosing the right grasses for the Colorado climate and more.

But one lawn maintenance technique that a lot of homeowners overlook is dethatching.

What is Dethatching and Why Should You Do It?

Dethatching is the process of removing thatch from your lawn. Thatch refers to the layer of mostly dead grass that builds up on the surface of your lawn between the shoots of living grass.

A little thatch is fine — it acts as a type of organic fertilizer for your lawn. But too much thatch can be a problem.

Thatch can block your lawn’s soil from getting enough nutrients, which makes life a lot harder for your grass.

Thatch buildup happens when some parts of grass don’t decay as quickly as other parts. The roots, stems, and crowns of dead grass can overstay their welcome, and eventually negatively impact the health of your lawn.

How Can You Tell If Your Lawn Needs Dethatching?

You can determine if your lawn needs dethatching by measuring the level of thatch. Once a year, dig up a small wedge of your lawn (in an out-of-the way corner), and measure the cross-section.

If the depth of the thatch is 1 to 2 inches (or more), then it’s time to for a dethatching.

What Time of Year is Best for Dethatching?

The best time of year to dethatch your lawn depends on the kind of grass you have.

Warm-season grasses (Zoysia, Bermudagrass) should be dethatched at the end of spring, or the very beginning of summer. Kentucky bluegrass and other cool-season grasses are better off dethatched at the end of the summer or in the beginning of autumn.

No matter what kind of grass you have, you shouldn’t dethatch when it’s dormant in the winter, or when it’s stressed — like in the dead heat of summer. The dethatching process will put extra stress on your grass, and if it’s already fighting against dry soil and hot air, you could end up damaging it more permanently. So you want to make sure it’s strong and healthy and able to quickly recover when you dethatch.

How to Dethatch Your Lawn

There are four different approaches you can take to dethatch your lawn. Choosing the best method for your lawn depends on how much thatch you have to deal with.

1. Use A Vertical Mower

A vertical mower (also known as a verticutter) is like a normal mower, except the blades cut down into your grass rather than across its surface. The blades are designed to pull thatch back up with them, removing it in the process.

You can set the depth of a vertical mower to the depth of thatch (which you measured earlier). This is a great option if your thatch is thick — like over 2 inches deep.

Your local hardware or lawn care store should offer verticutters for rent, which is a nice option if it’s a tool you won’t need to use very often.

2. Use A Power Rake

A power rake is a tool that combines the functions of a mower and a rake. The powered tines dig just down to the surface of the soil and pull up thatch.

This tool works well if your thatch is 1 to 2 inches deep. Deeper thatch will take multiple power raking sessions, which could end up stressing out your grass if you do it all in a short period of time.

Stores like Home Depot rent out power rakes — check with your local hardware store to see if they offer rentals.

3. Manually Dethatch Your Lawn

This dethatching approach involves using a non-powered dethatching rake. These tools are similar to a powered rake, except you have to work a lot harder!


Only consider manually dethatching your lawn if the thatch is relatively thin, around 1 inch deep. Any deeper and you’ll be at it for a long time — while putting your living grass under some serious stress throughout the process.

4. Hire A Professional Landscaper

No matter the thatch situation, a professional landscaper will get the job done right, saving you time and a potential back ache.

If your thatch is over 2 inches deep, hiring a professional may be the best bet for your lawn. Thick hatch will take multiple dethatching sessions to remove, and doing this incorrectly could damage your grass and its roots.

A professional landscaper will know how to properly dethatch your lawn. But how can you tell if a professional landscaper is really as quality as they claim to be?

Signs You Need to Fire Your Landscaper

Just because a landscaper says they’re a professional doesn’t mean they really are. It’s important to make sure your landscaping prospect has good referrals, positive reviews online, is communicative and reliable, and more.


Read our guide to how to avoid bad landscapers and how to find the right one for your lawn >