How to Dethatch a Lawn

The PropertyClub Team
Nov 7th 2020
When it comes to landscaping, thatch refers to the layer of living and dead plant material that collects between the grass and soil in your yard. Dethatching your lawn can improve its health but also enhance its appearance. 

Most of the time, a little bit of thatch in your lawn is actually a good thing as it facilitates the uptake of water and nutrients. However, too much thatch can be harmful and choke out your grass from the vital substances it needs. As such, every now and then, you should think about dethatching your lawn. 

Today, we will cover the why, when, and how of dethatching a lawn. Detaching is an important part of landscaping so pay attention!

Why Dethatch a Lawn?

Like we said, a little bit of thatch can be a good thing. Thatch acts kind of like a mulch. The dead plant material regulates the soil temperature, maintains a proper pH level, and can improve air circulation while broken down organic material provides the soil with nutrients. 

However, this organic layer can accumulate faster than it can break down and become too thick. Excess thatch can lead to the following lawn issues:

  • The barrier deprives the soil of water and vital nutrients
  • Insects and pests breed in thick layers of thatch
  • Lawn disease spreads more readily
  • The spongy layer keeps you from mowing your lawn evenly

All other things being equal, a thatch layer about ½” thick is ideal. Any thicker, and you might want to consider dethatching your lawn. 

When Should I Dethatch My Lawn?

Like most landscaping projects, dethatching goes best if you perform it during the growing season for your specific grass type. Active growth will help keep your lawn in good condition and aid in its recovery. For example, if you have cool-season grass, dethatching in the late summer or early fall. Warm-season grasses should be dethatched during the late spring and early summer. 

You can check your lawn’s thatch layer with a small spade. Dig up a small patch of your soil, and you should be able to measure the thatch layer. If it is thicker than 1” or your grass has already started to wilt and become discolored, then it’s time to dethatch.

When dethatching, it also might be a good idea to simultaneously aerate your lawn. Aeration upturns the soil, circulating oxygen and nutrients. Aeration and dethatching are different processes, but they have similar benefits. Aerating your soil also loosens up the thatch and makes it easier to remove. 

How to Dethatch a Lawn

If you want to dethatch your lawn, then you will need a couple of tools. The most important one is a rake for pulling up the thatch layer. The best kind of rake to use is a curved, short-tined rake to pull up the layer. You do not want the tines to be too long because then they might also pull up your soil rather than just the thatch. You could also buy a power-rake to make the job easier, but it is not necessary. Most home improvement stores have the right kind of rake you will need. 

Once you have all the tools, the first thing to do is mow your lawn to about half its normal height. This will make it easier for the rake-tines to grab the thatch near the base of the grass. You should also make sure you make a note of any irrigation lines or shallow pipes. 

Next, starting at one corner of the yard, go through and use the rake to pull the thatch up. Position the rake in the base of the soil and quickly pull back in short, upward motions. You will be able to see the thatch coming up, so you will know if your technique is worth it. Continue across your entire lawn, taking care not to pull up the soil as well. 

Once you are done dethatching, your lawn will look jagged and uneven. Using a different rake, sweep up the excess thatch and remove it. If any grass patches were pulled up, you could treat them with some extra seed and topsoil to fill in the bare spots. You should also take the time to fertilize your entire lawn once you are finished. Fertilizing your lawn afterward will help with its recovery.  

You should also try to water your lawn a bit more than normally after dethatching. Try to give it at least a nice covering of moisture once a day until it goes back to its normal color and thickness. 

How to Prevent Thatch Problems

Thatch is formed by leftover organic material from dead grass and plants. Thatch problems are caused by plant material accumulating faster than it can be broken down. So here are a few things you can do to avoid thatch problems in the future. 

  • Do not overwater your lawn. Too much water and prevent thatch from breaking down and cause it to accumulate too quickly. 
  • Use a fertilizer high in nitrogen content. Nitrogen helps break down dead material and is good for lawn health. 
  • Don’t use unnecessary pesticides. Some bugs such as worms (although worms technically are not bugs) are useful for soil aeration and breaking down thatch. Pesticides will kill the good insects along with the bad. 
  • Regularly rake dead leaves and grass clippings from mowing. These materials make up the bulk of thatch. 

The best way to deal with thatch problems is to prevent them from happening in the first place.

Conclusions

Thatch is a necessary part of a healthy lawn but left unchecked it can wreak havoc on your yard’s health. It would be best if you tried to dethatch your lawn at least once every 6 months to a year, preferably in the months leading up to your grass’s prime growing season. The key to managing thatch is consistent lawn maintenance so take care to pay attention and keep an eye on your thatch levels throughout the year.