How to scarify a lawn using a leaf rake —plus petrol or electric scarifier methods

Too mucb thatch can severely hamper the lawn's health
Too much thatch can severely hamper the lawn's health (Image credit: The Grass People)

Knowing how to scarify a lawn is essential part of maintaining a tidy and healthy garden.

Thatch, a layer of dead turf material, can cause a mossy and spongy lawn when it gets too thick because it stops water, fertiliser and oxygen from reaching the grass roots. However, the process of scarifying, also known as de-thatching, removes thatch, moss, and other matter from the surface of the lawn.

It can be done using a leaf rake or with a scarifier, a tool that uses rolling blades to trim and remove the unhelpful organic matter.

But first, a note of caution: be prepared for the fact your lawn will not look its best straight after scarifying, so don’t undertake the process the day before you enter a garden design competition.

Chris Mcilroy, of seed and lawn experts The Grass People, says: “Scarifying your lawn can make it look quite bad, but there’s no need to panic, things get worse before they get better.”

How to scarify a lawn: Step by step

Experts say the best time to scarify lawns is the months when the grass is generally growing strongly because it makes recovery much faster. Therefore, heavy scarifying should be done in March, April, September, and October and lighter scarification can be done in February and May.

1. Keep an eye on the weather

Chris recommends you always keep an eye on your weather app before you plan to scarify. Never do it during a cold snap, as you could end up causing more harm than good.

2. Use a leaf rake to scarify your lawn    

“We recommend using a leaf rake, not an ordinary rake, as this will rip lumps out of your grass rather than lifting the moss/thatch,” Chris said. “This is the simplest way, although it involves quite a bit of physical effort to do the whole area. "

Alternatively you can use a petrol or electric scarifier, which is talked about in more detail in the next section of this article.

3. Scarify small sections at a time

Guy Jenkins, consumer manager at Johnsons Lawn Seed, says the best way to scarify a lawn is to scarify small sections at a time. By doing this, you'll be able to see which areas have been completed and which still need to be done. 

4. Use a gentle tug technique to scarify

If using a leaf rake, Guy Jenkins says the technique is to "Use the rake to tug lightly into the thatch or moss and pull towards you, lifting the debris from the grass."

He adds: "Don’t rake roughly as this will damage the healthy grass and soil."

5. Scarify a lawn in one direction, then again at another angle

Both Chris and Guy say it is best to aim to rake in one direction first. Guy says to go over the same area of the lawn several times with Chris suggesting to do this at a slightly different angle to get more material. Often 90 degrees is chosen for this second angle for ease, but different angles work too.

6. Collect the thatch up afterwards

David Truby, the managing director of lawn care franchise Greensleeves says it is best to use a rake or leaf blower to collect all the thatch, moss and weeds from your lawn and responsibly dispose of it all.

7. Sow some grass seed

Your grass will need help to recover, so consider overseeding your lawn after you scarify it. This will help to fill out the bare patches and will also reduce the opportunity for weeds to grow in those bare spots. You can read up on how to sow grass seed in our guide.

Moss and thatch stops water and nutrients reaching the grass

Moss and thatch stops water and nutrients reaching the grass (Image credit: Greensleeves)

How to scarify a lawn with a powered scarifier?

You can also use a petrol or electric hand scarifier. These will scarify and remove thatch from your lawn without the physical effort of a leaf rake as well as helping to aerate the soil.

If you have a large area to cover, Chris recommends using an automated scarifier as this will speed up this process and save you a lot of effort. 

Chris adds: “You can hire or buy one if you have a large area to cover. This method will remove a lot more material and be useful if you want to overseed afterwards. This may result in seeing soil patches where the moss has been removed - but that is what you need to overseed, so don’t panic.”

This electric scarifier is a fairly inexpensive option or you can opt for a more pricey, but more heavy duty, Hyundai petrol scarifier and aerator, both from Amazon.

The technique when scarifying is actually very similar to the technique used for a leaf rake. You go over the lawn in one direction, before going over it a second time at a different angle. You then need to collect up all the thatch that has been pulled out afterwards and ideally seed more grass.

David adds that is worth bearing in mind that while scarification machines can be bought online and aren’t that expensive, they’re far more like motorised rakes and so shouldn’t be confused with or compared to the kind of machine professional lawn care experts use.

He said: “They are real monsters, employing powerful engines and blades to intensively cut down into the turf and vigorously extract thatch, moss and weeds.”

When is a leaf rake better to use when scarifying?

Guy points out that a manual scarifier such as a rake doesn’t use petrol or electricity so is good for the environment and your bank balance. He says rakes are ideal for scarifying smaller gardens and their size means they are ideal for small areas near hedges, trees, and shade which are more prone to moss.

He adds: "However, if you have a large garden a rake is quite time-consuming and requires more exertion than a machine scarifier which has sharp tines that rotate at high speed and vertically cuts turf."

Do you scarify before or after cutting grass?

Chris advises you mow your lawn a week before scarifying it. He said: “This will help to prepare your grass and will also help to remove any excess grass length and chop up any thatch patches, leaving your scarifying job much easier.”

He also recommends using a moss killer a week before you scarify. This will help to kill off the moss and it will make your job much easier when it comes to removing it. You can take a look at the best way to kill moss in our guide.

David adds: “On the day of treatment, you’ll immediately notice a large amount of organic matter being brought to the surface, but don’t worry. This is to be expected.”

Take a look at our guide on when to cut grass in winter and 'when should I stop cutting my grass?' for more information on mowing your lawn.

Sam Webb

Sam is based in Coventry and has been a news reporter for nearly 20 years. His work has featured in the Mirror, The Sun, MailOnline, the Independent, and news outlets throughout the world.  As a copywriter, he has written for clients as diverse as Saint-Gobain, Michelin, Halfords Autocentre, Great British Heating, and Irwin Industrial Tools. During the pandemic, he converted a van into a mini-camper and is currently planning to convert his shed into an office and Star Wars shrine.