How often should you dethatch a lawn? Expert tips for healthy turf

Q: I have recently moved into a suburban property with a large backyard lawn. Alongside mowing and aerating it, I've heard that dethatching can be beneficial. But how often should this be done – and is it possible to overdo it?

A: Dethatching is a valuable lawn care task that, when done properly, is essential for luscious, green grass. 

As Gene Caballero, the co-founder of GreenPal explains, thatch is a layer of dead grass, roots, and debris that accumulates between the soil surface and the live grass. If it becomes too thick, it hinders essential nutrients, water, and air from reaching the soil, and can also lead to problems with pests and diseases, he says.

The process of dethatching is relatively straightforward – as long as you have the correct tool (such as this Altdoff thatch rake from Amazon). However, getting the timing and frequency right is important. In fact, if you dethatch your lawn too often, you may end up damaging it.

Gene Caballero

Gene Caballero is the co-founder of GreenPal which has been described as Uber for lawn care. He has been in the landscaping business for over 25 years.

How often to dethatch your lawn

Keep your lawn in the best of health with these expert tips.

Only dethatch a lawn when necessary

The best time to dethatch a lawn is in early spring and fall, when the grass is growing. However, it should only be carried out if needed. Once a year is usually sufficient – and some lawn owners may need to do it even less than this.

Gene says it's vital not to overdo it. He warns that excessive dethatching can lead to a decline in your lawn's health, as it can damage the roots and the crowns of the grass and make it more vulnerable to lawn weeds and pests.

Bear in mind, too, that a small amount of thatch is actually a good thing. It works like a mulch for your lawn, helping the soil to retain moisture and protecting the roots from temperature fluctuations as well as foot traffic.

So, how can you tell when the time is right?

'Generally, you should only dethatch when the thatch layer exceeds half an inch,' says Gene. 

You can check for this by looking closely at the base of the grass, and identifying the brown and fibrous layer between the healthy grass and the soil. You can use a bulb planter or trowel to remove a small plug for easy inspection. 

Sod that feels spongey underfoot is another telltale sign that it's time to dethatch.

Reducing the need to dethatch

'With regular lawn maintenance, including proper mowing, watering, and fertilizing, you can prevent excessive thatch buildup, reducing the need for frequent dethatching,' says Gene.

Preparing the ground well before installing a lawn and aerating the turf often can also help to reduce the need for this lawn care task, particularly if you have heavy, clay soil in your yard.

FAQs

'Your lawn will be stressed after dethatching,' says Gene. 'It's imperative to water it thoroughly and consider following up with a high-quality fertilizer for recovery.' It's also a good time to overseed it, to help your turf quickly bounce back to full green glory.