What a lawn scarifier is, and how to use it

If you’ve ever wondered what a lawn scarifier is and how to use it, take a look at our handy guide.

What is a lawn scarifier?

A lawn scarifier, sometimes referred to as a ‘dethatcher’, is a garden tool that is designed to cut through the soil, helping to remove dead moss and other debris like grass cuttings. The cutting action of the tool, either powered by electricity or a manual push action, also helps to aerate the soil, making it healthier, (almost) weed free and longer lasting.

Using a motorised scarifier

The consequences of not scarifying your lawn and keeping up with other maintenance jobs can be devastating. If dead grass cuttings and moss are allowed to sit on the lawn’s surface they can prevent rain water from draining deep under the ground where it’s needed the most. Much of the water and moisture will sit on top making your lawn soggy and looking very sorry for itself. The layer of dead grass that sits on top of a lawn is sometimes known as a ‘thatch’, which explains the ‘dethatcher’ reference. Excess moisture can also encourage more moss growth, making the problem even worse.

How to use a lawn scarifier

So now you know what a lawn scarifier actually is, let’s take a look at some top tips on how to get the best out of your new garden tool.

Remove any debris from the lawn and apply a moss killer, rake out the dead moss in advance of scarifying

A few weeks before you intend to use a lawn scarifier, inspect your lawn for any live moss or debris. You need to get rid of this before you do anything else. Using a good moss killer, spread this over your lawn as per the instructions. This is a very important step as you don’t want to be spreading the airborne spores of living moss all over the garden with your scarifier, encouraging a moss epidemic!

Mow the lawn on a low setting

Once you are sure that the moss has died (it should look black or brown and dry) mow your lawn on a dry day, with the mower on a low setting. Doing this before using the lawn scarifier will mean that you can collect the cut grass simultaneously at the end of your job, before it has time to do any harm.

Scarify the lawn on a high setting

Start with the lawn scarifier on a high setting and go over the surface a couple of times. Then repeat the process at angles but reduce the severity of the settings on each pass.

Apply top soil and grass seed to finish

As an optional extra you could choose to add some more grass seed at the end of the process, a great idea if your lawn is looking tired. You should then cover the seed with a mixture of some fine compost and sharp sand to protect them while they germinate. This technique is often referred to as ‘over seeding’. With a little TLC your grass will be looking as good as new in a week or so.

When to use a lawn scarifier

The ideal time to scarify your lawn can vary depending on your location and the weather, but as a guide the best time is when the turf growth is at its most prolific. This growing season is normally in the autumn or late spring. As far as frequency goes, once a year is normally sufficient, or more often if your lawn is in bad condition with a lot of moss growth. Scarifying your lawn can take its toll on the grass and roots so you should always err on the side of caution.

Are there any alternative tools?

When scarifying your lawn there are actually other tools you can use to get a similar if not identical result. A simple garden rake is the most popular scarifier alternative, allowing you to control the pressure you put on the lawn with a more lightweight tool.

Manually scarifying a lawn using a rake

Depending on the size of your lawn you could use a small trowel to remove debris and a fork to aid aeration of the soil. There are also a number of combined tools on the market that incorporate a scarifier and rake allowing you to choose between the two functions. If you’re just looking to aerate, then why not try out a pair of lawn spikes.

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