Lawn Scarification: Why, When and How to Scarify Your Lawn (The Ultimate Guide)

lawn scarification

If your lawn looks tired, lacks colour or is a bit threadbare, then lawn scarification could breath new life into it.

In this guide, we’re going to dive deep into why you should scarify, when you should do it and how to scarify your lawn properly. We’ll even show you what you need to do afterwards to make sure your lawn recovers and looks better than it ever has.

To get the best results when you scarify your lawn, I encourage you to read this guide fully, at least once, it’ll take you around 15 minutes.

Then, bookmark the page so you can come back to it, even print it if you have to!

 

What is Lawn Scarification and Why Do I Need to Do it?


Lawn scarification is the process of removing thatch from your lawn, which is why some gardeners refer to it as ‘de-thatching’. Thatch prevents water, oxygen, and nutrients from getting into the root zone of the grass.

Removing this thatch via scarification enables water, oxygen, and nutrients to penetrate the soil. This improves the health and colour of your lawn.

What is Lawn Thatch?

lawn thatch

When a grass seed is fertilised it doesn’t just grow upwards as a blade of grass, it grows side shoots or ‘runners’.

These runners can grow above the surface of the soil (called Stolons) or just below the surface (called Rhyzomes). They help the grass to spread and create a lush, thick coverage. It also causes the turf to knit together and become dense, which is what you need for a healthy, good-looking lawn.

Over time, grass and the runners die and get replaced with newer, healthier, stronger grass.

This dead grass contains a chemical compound called Lignin which makes it very slow to decompose. As a result, layers and layers of dead grass build up and mix with newer shoots. This is thatch!

What’s the Right Amount of Thatch?

Having some thatch (around a quarter of an inch) in your lawn is a good thing. It protects the crown of the grass plant, while still allowing water, oxygen, and nutrients penetrate the soil and get into the root zone.

That said, too much thatch stops new grass from growing which opens the door for other problems, like moss infestation, weeds like Black Medick or Mushrooms and fungal diseases.

How much thatch is too much?

If you’ve got half an inch or more, you’ll need to scarify.

Not All Lawns Contain Thatch

Not all grasses produce thatch.

Ryegrass is a common example. It has broad leaves, is dark in colour, very hard wearing and doesn’t produce much thatch at all. That said, if you’ve never scarified or haven’t done for a few years, there will probably be a build-up.

This makes ryegrass perfect if you’re not very green fingered and you’d rather not spend your days maintaining your lawn. On the other hand, many serious gardeners see ryegrass a weed that must be eradicated.

If you want your lawn to look like a perfectly manicured bowling green, you don’t want rye grass in it.

You also better get used to scarifying!

How to Check For Thatch in Your Lawn

Before you scarify or de-thatch your lawn, you need to know whether or not a build up of thatch is the reason that your grass lawn looks tired in the first place.

Scarifying just for the hell of it can cause major damage which could take your lawn months to recover from. You MUST check how much thatch is present before hitting it with such an invasive treatment.

So how do you do it?

Simple!

You take samples.

Using a bulb planter, a trowel, a hollow tiner, or even a spade, dig out a small sample from various places in your lawn. It doesn’t have to be a big sample, just make sure it’s at least a couple of inches deep.

These samples will show you how much thatch is present in your lawn (see image above).

 

The Difference Between Scarifying and Raking


Quite often, the terms ‘scarifying’ and ‘raking’ are used interchangeably but the fact is, they’re very different procedures.

Scarifying

scarifying

As you now know, scarifying is dictated by the amount of THATCH you have in your lawn.

Thatch builds up just under the surface. A scarifier, either a handheld or a powered machine uses vertical blades to cut into the surface and remove the thatch from underneath.

This cutting action also creates the perfect bed for new grass seed to grow in, which in turn, aids recovery.

Raking

raking

Raking is dictated by the amount of MOSS you have in your lawn.

Moss doesn’t root and therefore grows on the surface of your lawn, in amongst the grass. A rake, either a springbok rake or a powered lawn rake has metal tines which are perfect for pulling moss away from the surface of the lawn.

If you have a lot of moss in your lawn, it’s a good idea to rake it out before scarification.

A word of warning though, raking a lawn by hand using a springbok rake is exhausting and will most likely result in blistered, very sore hands.

 

When to Scarify Your Lawn


It’s important that you understand…

…Lawn scarification is very beneficial in the long term but in the short term, it’ll make a mess. And if your thatch problem is particularly bad, you could lose most of your lawn.

You might finish with the scarifier, look at your lawn and think, ‘What the hell have I done?!’

But fear not, your lawn will recover and look better than it ever has. The key is to make sure your lawn recovers as quickly as possible. This means choosing the best time of year to scarify.

In order for your lawn to recover quickly, you need to scarify in seasons that provide good growing conditions. This means, a mixture of warmth, rain and sun. You want to avoid excessive heat and cold.

The very best time of year for heavy scarification is in the Autumn but light scarification can be done in Spring.

Spring: For Light Scarification

If you have a bit of moss in your lawn, light scarification, (or raking) can be done as part of your spring lawn repair procedure. With either a hand scarifier, springbok rake or an electric lawn rake.

April is generally a good time for this as the weather starts to warm up but there’s still plenty of rain to aid recovery.

Autumn: The Best Time of Year For Heavy Scarification

If your lawn has heavy thatch, a bad moss infestation or has suffered from Dry Patch during the summer, you’ll need to scarify quite heavily.In which case, wait until the autumn.

The back end of August (providing it’s not too hot) and through September is usually a good time to do it. It’s also a good time to aerate your lawn which can be done after scarifying and before overseeding and fertilising.

But why Autumn?

Well, when you scarify you essentially cut into the earth and tear out thatch and moss which leaves bear, open soil. As I have already said, if your thatch problem is particularly bad you could lose most of your grass.

This open soil is the perfect seed bed to spread and fertilise new grass seed which helps your lawn recover. But if you were to do this kind of invasive treatment in the Spring, this open soil would also be the perfect bed for weed seeds. The end result is that you fix your moss or thatch problem and replace it with a weed problem.

By waiting until Autumn, you’ll avoid most of the year’s weeds and your lawn can recover without being taken over by Dandelions and other weeds.

Dry Afternoons: The Best Time of Day to Scarify

Scarification is best done on a dry day in the afternoon.

You don’t want to scarify when it’s wet for a couple of reasons;

  1. It’ll just make the job harder as wet thatch, moss and grass can get tangled and clog up your machinery.
  2. It’s a nightmare to clean up afterwards.

So pick a dry day and wait until the afternoon when the sun has dried and dew in the grass.

 

Tools & Equipment For Scarifying


Here is a list of everything you need to complete the job.

lawnmowerLawnmower

This is to cut the grass short which makes scarifying easier.

If your lawnmower has a grass box that collects grass as it is cut, you can use it to ‘hoover up’ the thatch to get rid of it instead of raking it.

moss killerMoss Killer (If You Have a Moss Infestation)

If there is a lot of moss in your lawn, it’s advisable to put a moss killer down 7-10 days before scarifying.

This will kill the moss and turn it black, making it far easier to remove it during scarification.

Read: The Best Moss Killers and How to Use Them

weed killerWeed Killer (If You Have Lots of Weeds)

If you have a lot of weeds in your lawn, get a good weed killer and give them a spray approximately 3 weeks before you scarify as part of your preparation.

Make sure you get a weedkiller that only kills weeds and not the grass too.

Read: The Best Weed Killers and How to Use Them

scarifierScarifier

Whether it’s a hand-held, electric or petrol scarifier, you need one to remove the thatch from your lawn.

You can’t do the job without one!

Read: The Best Lawn Scarifier: Manual, Electric or Petrol?

garden rakeRake

You’ll need a rake to gather up all of the moss and thatch that scarifying brings to the surface.

As I mentioned before, if you have a lawnmower that collects grass as it cuts it, you can use this to speed up the process instead.

grass seedGrass Seed

Once you’ve scarified your lawn it’ll probably be very thin and patchy. If the thatch or moss problem was particularly bad, there might not be much grass left at all.

This means you’ll need to replace it with new grass seed.

The type of grass your lawn is already made up and how you use you your lawn will dictate which type of grass seed you choose.

Read: Grass Seed Reviews and Buyers Guide

lawn fertiliserFertiliser

In order for your lawn to recover as quickly as possible, the ground needs to be fertile.

If it has been covered in moss or thick with thatch, water and nutrients wouldn’t have been able to penetrate into the soil. You need to help it along with some good quality fertiliser.

Read: What’s the Best Lawn Fertiliser? My 6 Best Recommendations

seed fertiliser spreaderGrass Seed and Fertiliser Spreader (Optional)

If you have a small lawn to cover with grass seed and fertiliser you can do it fairly evenly by hand.

However, if you have large areas of grass, doing it by hand can be pretty time consuming and not very accurate. In which case you should consider investing in a spreader.

 

How to Scarify Your Lawn: A Step-by-Step Guide


As I have already mentioned, scarification is a pretty harsh procedure which if you don’t do properly, can cause more problems than it fixes.

That’s not to say you should be scared of doing it though. You just need to plan ahead, make sure you’ve got all the tools for the job and commit to doing it properly.

Preparing Your Lawn For Scarification

Like a painter and decorator will tell you, a good finish relies on good preparation. Lawn scarification is no different.

So how do you prepare your lawn for scarification?

3 Weeks Before Scarifying: Kill Any Weeds

If you’ve got weeds like dandelionsdaisies, or white clover in your lawn, give them a spray with a good weed killer. Do this when the leaves are big as they will absorb the chemicals and take them into the roots.

If you’ve kept on top of your weeds as part of your regular lawn care schedule, weeds shouldn’t be a major problem.

2 Weeks Before Scarifying: Gradually Bring the Height of the Grass Down

You don’t want to just scalp your lawn as this will shock the grass. Grass is 85% water so if you cut it down by half, you take 50% of its water, as well as its food and ability to make food. This can make the grass weak and in the worst cases can kill it.

As you’re trying to breathe new life into your lawn, this isn’t a good idea!

Start by just taking the top of the grass and then reduce the mowing height by one setting every 3 or 4 days until the grass is around 5cm high.

If you don’t have a moss problem, keep reducing the mower height until it is on its lowest setting.

1 Week Before Scarifying: Apply a Moss Killer (If You Have a Moss Infestation)

If you do have a moss problem, put down a moss killer 7-10 days before you plan to scarify.

Moss can be difficult to remove if not treated beforehand. When you apply a moss killer it’s much easier to remove.

The Day Before You Scarify: If You’ve Applied a Moss Killer, Rake the Dead Moss Away First

As I’ve already said, raking and scarifying are two different things. Don’t just scarify assuming it will remove all the moss too.

It will remove a lot of it but you’ll find that it’ll leave some lying around. So for best results, rake first, and go over it a couple of times to get rid of as much as you can.

If you’re using a springbok rake, be prepared for it to take hours. A powered lawn rake can have the job done inside an hour (depending on the size of the lawn and the amount of moss) so it’s well worth the investment. Especially if you live in a clay soil area as moss will be a constant battle.

Scarifying Your Lawn

Whether you use a handheld scarifier or a powered machine the best advice is to go gently. The idea is to cause as little damage as possible. Your lawn will still look like a wreck when you’ve done but the gentler you are, the quicker it’ll recover.

Depending on how bad the thatch problem is, you might find you have to make several passes with the scarifier. But my advice is to go over your lawn twice and see how things look, then make a decision.

The First Pass

How to Scarify a Lawn

On your first pass, start in the corner and scarify along the long edge of your lawn. Then, take a step into the lawn, turn around and come back the other way, in exactly the same way as you’d mow the lawn. Go up and down the until you have scarified the whole lawn.

When you have done, gather up all of the debris with a rake to clear the lawn. If your lawnmower collects grass as it cuts it, you could use this instead, it’ll act as a hoover and suck it up.

At this point, it’ll start to look a little rough but we’re not done yet. You need to go over the lawn a second time.

The Second Pass

scarifying a lawn

Do the second pass at a 45-degree angle to the first pass so you go diagonally across the lawn. If you do the second pass 90 degrees the first one, you’ll damage the lawn more than you need to and recovery will take longer.

Once you’ve made your second pass, collect the debris.

If on the second pass a lot of material comes out of your lawn, go over it a third or even fourth time. Each pass should be done at 45 degrees to the last.

On each pass, you’ll find less and less material will come out of the lawn.

The Last Pass

On your last pass with the scarifier, use the blades to cut into the soil about a quarter inch deep. This will make the perfect bed for laying new grass seed.

 

How to Use a Scarifier


Now you know how to scarify a lawn, let’s look at the two different types of scarifier and how to use them to best effect.

The following video from the Lawnsmith is excellent.

Using a Handheld Scarifier

If you only have a small lawn, a hand-held scarifier should do the trick and they’re very simple to use.

Start off in one corner of the lawn and continue down the long edge. Use a back and forth motion and vary the angle of the handle. The higher you raise the handle, the deeper the blades will penetrate the lawn and the more thatch will be removed.

When you make your last pass, you’ll want to raise the handle quite high so the blades cut into the soil to create an open bed for seeding.

Even on a small lawn, using a hand-held scarifier takes significantly longer than a powered version. For that reason, I always use a powered scarifier.

Using a Powered Scarifier

If you’re using an electric or petrol scarifier, it’s just a case of adjusting the height and pushing it around in exactly the same way a lawnmower.

Because you have the option to adjust the height, you might be tempted to set it to its lowest setting and go as deep as you can.

Don’t do this!

Remember I said earlier, the best advice is to go gently. Being too rough with a powered machine can result in big chunks of turf being ripped out of your lawn.

So, find a path, patio or hard surface and adjust the height on your scarifier so the blades just touch the floor. Then, turn it on and go over your lawn for a few meters. Keep making minor adjustments until the thatch comes up without tearing great chunks out of your lawn.

On your last pass, you’ll want to cut into the soil about a quarter inch deep to create a seed bed. To do this, adjust the height accordingly.

 

What to Do After Scarifying Your Lawn


After a treatment as invasive as scarifying, you need to help the lawn recover.

As I’ve said several times in this article already, once you have scarified your lawn it’s going to look a mess.

Recovery will be made easier if you’ve timed it well and the weather helps by providing some sun, warmth and rain.

But in order for it to recover quickly and look the best it ever has, you need to help it along.

There are two things you need to do;

  • Overseed your lawn, then
  • Fertilise it

Overseed Your Lawn

how to overseed a lawn

Overseeding is very simple to do but many people don’t bother. Maybe because they think it’s more difficult than it is or because grass seed isn’t cheap.

But if you don’t overseed after scarifying your lawn it’s guaranteed to take more time to recover than it should. As a result, your lawn will look unsightly and the probability of a weed infestation in the spring will be much greater.

By overseeding, your lawn will recover and look better sooner. Also, when your grass is thick and lush, there is less room for weeds to grow.

Read: Why, When and How to Re-Seed Your Lawn

Apply a Fertiliser

lawn fertiliser

If you have had a thatch problem or a moss infestation, chances are that the soil has been lacking in three key nutrients;

  • Nitrogen – makes grass grow and become greener.
  • Phosphorus – stimulates root growth and seed development.
  • Potassium – strengthens grass against disease and drought.

Applying a fertiliser will put much these much-needed nutrients back into the soil and help the grass seed germinate and grow quickly.

If you overseed without fertilising, the soil might not have enough nutrients in it to germinate the new grass seed.

Read: The Best Lawn Feeds and When to Use Them

 

Now it’s Over to You


After reading this guide you might feel a bit overwhelmed, or, you might feel excited to get started.

If you’re thinking it’s too big a job, stop worrying because it’s actually very simple. Just give this article another read, consider what tools you’ll need for the job, take your time and have a go.

Your lawn will thank you for it!

If you have any questions, please leave a comment below.

I’d also love to see your before and after pictures too!

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