What Does Dethatching Do For
Your Grass?

Thatch is a layer of living and dead grass shoots, stems, and roots which form between the green grass blades and the soil surface. This layer can often contain decaying fallen leaves, flowers and other garden debris.

If thatch is left to build up, it can attract and harbor damaging insects such as chinch bugs.

This damage manifests in the appearance of grass suffering from drought; your grass blades wilt, turn yellow-brown, then dry out and die.

Thatch also reduces the amount of oxygen and moisture that is able to reach the soil and grass roots. Not only does this stunt the growth of grass, but it can inhibit water draining away, leading to a muddy pitch during the rainy seasons.

With thatch fully removed, grass becomes much more responsive to fertiliser, and pesticides become an order of magnitude more effective.

Dethatching (sometimes referred to as scarifying) involves removing the layer of decaying plant matter to allow your grass to breathe, and to remove the inviting habitat for pests.

There are a variety of dethatching processes to choose from, depending on the severity of thatch.

Debris accumulates over the winter months as the leaves fall. Grass will struggle to recover from a winter dethatch, so it is best to wait until the Spring.

Similarly, some grass will die in the summer heat, which makes Autumn an ideal time to remove this build up.

As with most lawn care treatments, you will want to stay off the grass during rain, frost and snow.

The most common type of dethatching is performed with a scarifying rake. These can be small or large, depending on the type of towing vehicle and surface area of your grass.

SCH 3SR Mounted 60 inch Scarifying Rake Pictured: SCH 3SR Mounted 60" Scarifying Rake


This type of dethatcher uses rows of heavy duty spring coil tines to pull and tease out the dead thatch and mat.

The spring mounted tines ‘jigger’ over the ground, and are designed to cause minimal damage to the grass, which can be a concern on uneven turf.

After this process is completed, it is advised that the dislodged thatch is removed by running over the area with a lawn mower and collection bag, or with a lawn sweeper.

If neither of these are available, the thatch will still decompose much quicker than it previously would.

For heavily thatched lawns, a much more aggressive process can be carried out with a powered rotor raker. A rotor rake uses many rows of free floating blades, which are powered by a petrol engine.

SCH RR3 Rotor Raker Pictured: SCH RR3 Rotor Raker


The blades should be set above the soil level, and will remove the vast majority of thatch in one pass.

This is best performed in Spring to early Autumn, as the grass needs time to recover before winter sets in.

Not only does a rotor raker remove thatch, but the minor trauma to the grass encourages growth, resulting in a thicker, more resilient lawn.

The debris created from the above process needs to be removed, which can be done with a lawn sweeper, mower or a rake, if first left to dry in the sun.

Another method uses a chain harrow. The tines of the harrow protrude downwards, and pull at the ground, removing thatch and dead grass.

This should only be used on paddocks and rough land with longer grass, as your finely trimmed golf green will be severely torn up.

A three-way chain harrow is the most versatile option for fields, and is recommended if you have a variety of grass lengths to maintain.

SCH MCH 48 inch Mini Chain Harrow Pictured: SCH MCH 48" Mini Chain Harrow


This harrow can be pulled in three different directions to suit the desired effect.

The tines protrude more if pulled in one direction creating an aggressive application. If the tow bar is changed to the other end of the chain harrow, the tines protrude less, creating a passive application.

The harrow can also be turned upside down for levelling grassed areas and mole hills.

Finally, we get to the least invasive process.

A moss rake is suitable for very fine lawns, such as bowls or tennis courts.

Despite its name, a moss rake is designed to remove more than just moss, and doubles as a light-duty scarifying rake, which won’t damage delicate pitches.

SCH HGM 40 inch Heavy Duty Moss Rake Attachment Pictured: SCH HGM 40" Heavy Duty Moss Rake Attachment


The many sprung-steel tines pull at the surface in the same style as a scarifying rake, however they exert less force onto the surface.

No matter the severity of thatch, dethatching will achieve healthier grass which is more resilient to pests and disease.

Air, water, nutrients, and fertilizer can reach the soil easier, plus your lawn can drain more effectively.

Assess your surfaces requirements before investing in scarifying equipment for best results.

We offer a variety of chain harrows, rotor rakers and scarifying rakes, some of which are attachments for interchangeable lawn care systems.

These systems allow a cost-effective solution to dethatching, aerating, slitting, brushing, rolling and more, all in one machine. To view our entire grass care range, please click here.

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Written by Zaros Machinery

Experts in Garden Machinery for the British Climate.