Get to the Root of the Problem: Understanding Lawn Thatch and How to Control It for a Healthier Lawn

If you are a lawn enthusiast, you know the importance of maintaining a healthy lawn. One of the most common problems that homeowners face is thatch build up.

Thatch is a layer of organic matter that accumulates between the grass blades and the soil surface. While a thin layer of thatch can be beneficial for your lawn, an excessive amount can lead to several problems such as drought stress, diseases, moss and pests.

In this article, we will discuss when and the best way to remove thatch from your lawn and how to prevent excessive thatch build up.

Is lawn thatch good or bad?

A thin layer of thatch, up to half an inch, can be beneficial for lawns. It can act as insulation, protecting the soil and roots from temperature extremes. Thatch can also help retain moisture and nutrients, promoting healthy growth. However, when thatch builds up to more than half an inch, it can become a problem.

Excessive thatch can prevent air, water, and nutrients from reaching the soil, leading to shallow root growth and a weak lawn. Thick thatch can also provide a breeding ground for pests and diseases, such as grubs and fungi. Therefore, it’s essential to monitor and manage thatch accumulation in your lawn.

When to remove thatch from your lawn

The best time to remove thatch from lawns is during the active growing season, which is usually in the spring or autumn. This is when the grass is actively growing and can quickly recover from the stress of scarifying. Avoid scarifying during the summer months or when your lawn is dormant, as it can cause more harm than good. The exception is in August if you are renovating your lawn and want to take advantage of the warm soil and wet weather to come.

It is also important to consider the severity of thatch build up before dethatching. If you have less than 25mm of thatch, it may not be necessary to scarify your lawn, especially if the lawn is maintaining the thatch level at this rate. A thin layer of thatch can actually be beneficial for your lawn as it can act as a natural fertiliser.

Best way to remove thatch from your lawn

The best way to remove thatch from the lawn is by using a scarifier or a power rake. A scarifier is a tool that uses vertical metal blades to cut through the thatch layer and pull it up to the surface of the lawn for removal. A power rake, on the other hand, uses tines, usually sprung, to pull the thatch up to the surface.

A scarifier is used for heavy thatch whereas a power rake is for very light more frequent work. Both tools can be rented from your local hire shop.

Before using a scarifier or a power rake, mow your lawn to a height of 15-20mm. This will make it easier for the tool to reach the thatch layer. It is also recommended to water your lawn a day before scarifying, as it will soften the thatch and make it easier to remove.

After dethatching, you’ll need to remove the debris from the lawn using a rake or a lawn vacuum. You can also leave the thatch on the lawn and let it decompose, which will add nutrients to the soil. However, leaving too much thatch on the lawn can suffocate the grass and lead to further problems.

Step by step to remove thatch from your lawn

To remove thatch from your lawn, follow these simple steps:

  1. Mow your lawn to a height of 15-20mm.
  2. Water your lawn a day before scarifying.
  3. Rent a scarifier or power rake from your local hire shop.
  4. Adjust the blades or tines to the appropriate depth.
  5. Start scarifying your lawn, making sure to overlap each pass.
  6. Rake up the thatch and dispose of it properly.
  7. Water your lawn to help it recover from the stress of scarifying.

How to manage lawn thatch

Preventing excessive thatch buildup is the best way to avoid thatching your lawn. Here are some tips to help you manage thatch:

  • Mow regularly and at the correct height – Mowing too low can damage the grass and promote thatch buildup.
  • Don’t over-fertilise – Excessive fertilisation can lead to fast grass growth and more thatch accumulation.
  • Water deeply but infrequently – Frequent watering can promote shallow root growth and thatch buildup.
  • Aerate the lawn – Aerating can help break up compacted soil and promote healthy root growth, reducing thatch buildup.
  • Use a mulching mower – A mulching mower can chop up grass clippings and return them to the soil, reducing thatch accumulation.


Removing thatch from the lawn is an important part of lawn maintenance. A thick layer of thatch can lead to several problems, but it can be easily removed using a scarifier or a power rake. Remember to scarify your lawn during the active growing season and only if the thatch build up is more than 15-20mm. By following these simple steps, you can ensure that your lawn stays healthy and lush for years to come.

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