Why, How, and When to Scarify Your Lawn

Why, How, and When to Scarify Your Lawn

31st Mar 2021 Scarification

Over time, thatch builds around the base of your grass plants, formed by grass clippings and other dead organic matter and debris. If left to build up, this layer ends up preventing air, water, and nutrients from reaching the soil and weakening your lawn.

To prevent thatch build up and maintain your lawn lush and healthy, regular scarification is needed. In this blog, we will look at what scarification is and talk you through why, when, and how you should scarify your lawn. 

What is lawn scarifying? 

Scarifying, also known as detaching, is the process of removing excess thatch buildup, moss and debris from around the base of your grass plants. 

Why is scarifying important?

Scarifying your lawn regularly is essential to its proper growth and health, as thatch creates a number of issues that can severely affect the development of your lawn.

Thatch causes shallow rooting

Thatch build-up prevents air, water, and nutrients from reaching the soil. Over time, seeking moisture and nutrients, grass plants root into the thatch layer instead of the soil beneath. 

This kind of shallow rooting leads to a spongy and irregular grass surface and leaves your lawn more prone to drought, as thatch rapidly dries out in the summer months. 

Thatch build-up encourages moss and disease

While a thin layer of thatch can prevent your solid from drying out, excessive thatch buildup soaks up water and maintains moisture, creating the perfect environment for moss and fungal diseases to develop and thrive. 

How to scarify a lawn?

Scarifying can be done by hand, with a springbok rack, or by using an electric or petrol-based scarifying machine. What method is best to use will depend on the size of your lawn as well as the amount of thatch build-up present. 

Before scarifying

Scarification puts a significant amount of stress on your lawn, but there are a few things you can do in order to prepare your lawn for the process. 

  • Establish the depth to which you need to scarify. Your aim is to scratch the surface of the soil, but ensure that you are not ripping out the grass roots. 
  • Mow your lawn a week in advance to trim your grass.
  • Apply a moss and weed treatment to your lawn, and use a hand rake to remove any dead moss and debris. This will prevent moss from further spreading in the process of scarifying.
  • Make sure your grass is not wet or too dry. Wet the grass a couple of days ahead or give it a couple of days to dry after heavy rainfall.

How to scarify by hand

To scarify your garden lawn using a springbok rake, you’ll need to vigorously rake through the grass. Work on small areas at one time, raking in one direction, then move on to raking the same area in the perpendicular direction. Raking by hand will sufficiently remove low levels of surface thatch.

How to scarify using a scarifying machine

For more established layers of thatch and bigger lawns, we recommend hiring an electric scarifying machine. Electric scarifiers are able to reach deeper levels of thatch, as well as providing the additional benefit of allowing you to set the depth to which you wish to scarify. 

Use the scarifying machine to mow small sections of your lawn at once, reviewing your progress as you go to make sure that you are not removing more than the necessary amount of thatch. Starting by scarifying in one direction, and move on to scarifying in the perpendicular direction once you have gone over your whole lawn.

When to scarify lawn?

Late summer and early autumn is the ideal period of the year to scarify your lawn in the UK, as warm and humid weather allows grass to thrive and quickly recover after scarifying. 

Scarification should always be carried out during months of growth, when your lawn is strong enough to recover from the process. Late spring weather may also be suitable for scarifying, but you should always avoid scarifying during the colder months.

How often should you scarify your lawn?

Once a year is a good rule of thumb when it comes to scarifying your lawn. Ideally, we recommend that UK lawns are scarified twice a year, once during the autumn, to remove the bulk of the thatch, followed by a lighter scarifying during spring, which will help get rid of any remaining winter debris. 

Even though most lawns will need regular scarifying to thrive, how often you should carry out this process also depends on the type of grass on your lawn. Fine grasses like fescue and those used in turf production are more prone to producing dense layers of thatch, while many of the modern rye grasses common in UK lawns do not produce much thatch. 

What to do after scarifying your lawn?

To see real benefits, your garden to-do list does not end once you’re done scarifying. As we’ve mentioned, scarification can be a fairly harsh process to your lawn, so it is important that you take the necessary steps to help it recover as quickly as possible. 


Aerating your lawn after scarifying will help further improve the flow of air, water,  and nutrients into the soil. You can read more about why and how you should aerate your lawn on this blog


You may be surprised with the amount of matter that you remove the first time you scarify. Once all the excessive thatch, moss, and organic debris is removed from your lawn, it’s likely that you will have some thinned out and bare patches. 

Overseeding is essential not only for aesthetic purposes but also to fill out the gaps in your lawn that would otherwise give way to weeds to take over your garden.


Applying fertiliser will help the new seeds germinate and replenish your lawn with the nutrients and minerals it needs to grow strong and healthy. To provide your lawn with what it needs, make sure to apply the right fertiliser for the time of the year. 

So & Mo’s Performance Liquid Lawn Feed is delivered as a 12-month plan with 6 feeds engineered to work with your lawn throughout the seasons, delivering year-round performance. 


After running through the necessary steps to get your lawn back on track to health, watering will encourage the germination of the new seeds and activate the newly applied fertiliser. 

Of course, if you are expecting rain, then you can always wait and let mother nature do the work for you. 



About So & Mo 

So & Mo have over 30 years of experience in maintaining some of the best garden lawns in the country. We produce a variety of high-quality products that will help you maintain your garden in top shape, including lawn feed, moss and weed control, and grass seed

Find out more about our products here or find further advice on how to care for your lawn on our blog

Ready to be proud of your garden?

Ensure your lawn never goes hungry with our personalised subscription.

  • Shop Now
  • Performance Lawn Feed

    Ensure your lawn never goes hungry again

    • Liquid lawn feed for super easy, precise application
    • Year round performance with only six annual feeds
    • See visible results in just three days!