How to scarify a lawn
Lawn scarification improves the health of your matted grass by decongesting it. Our guide explains the best time to do it, and just how it works.
20.11.2024
Overview: how to scarify a lawn
- Use a scarifier to remove thatch and moss to aerate the lawn.
- Mow the lawn to a height of 2 to 3 centimetres in advance.
- Scarify young lawns after 2 to 3 years at the earliest.
- Work evenly across and down the lawn, penetrating no more than 3 to 4 millimetres into the soil.
- In very clayey or compacted soils, sand the lawn after scarifying.
The best time for lawn scarification is in spring. The months of October and November are ideal, as the soil regenerates very quickly in late spring. However, you can also scarify your lawn in autumn if necessary.
A matted or moss-covered lawn should be scarified once or twice a year. A healthy lawn does not need to be scarified.
However, a freshly laid lawn should not be scarified for at least 3 years.
Yes, a mild, dry day between September and March is generally the right time to scarify your lawn. But not if the ground is cold - it should be 10°C or more. That is why October and November are the best months.
In order to prevent the plants from drying out due to the intense heat during the summer, we recommend that you do not scarify.
No, you should not scarify your lawn during or immediately after rain. Wet grass hinders the rotation of the scarifier blades, making it more difficult to remove thatch and preventing the ground from being optimally cleaned.
When scarifying, they should penetrate the turf to a maximum depth of two to three millimetres.
Why should I scarify my lawn?
Scarifying simply refers to the process of using a tool to clear matted grass and moss from the surface of your lawn, and lightly opening up the ground to add air and improve growth. Verticutting is similar, though it has less impact on the soil itself. Left alone, debris and dead matter in grass can form a matted layer of thatch that will prevent water from reaching the roots and eventually suffocate the lawn.
How does lawn scarification work?
To scarify your lawn, you need to use special equipment that cuts vertically through the lawn and thatch, and shallowly scores the surface of the earth. You can achieve a similar effect using just a rake, but it is back-breaking work! We recommend scarifying tools with rotating blades that penetrate a few millimetres into the soil to remove moss, thatch and weeds. The process can make a bit of a mess of the grass at first, but it rejuvenates your lawn for the long term, making it easier for air, water and micronutrients to reach the roots.
The best time to scarify
October and November are the best months, as your lawn is growing strongly; but you can scarify between September and November, and in March, depending on the weather. You should ideally scarify your lawn twice a year, but not when the ground is cold – it should be at 10°C or more. Equally, if the weather gets too hot, it’s best to postpone lawn scarification to prevent the lawn from drying out.
Scarifying in spring
Spring is the best time of year to scarify a lawn. As soon as temperatures are consistently above 10°C and the grass is growing vigorously, the lawn should be strong enough to scarify – after it has been mown three or four times since the beginning of the year. Start your lawn care by scarifying, followed by the first fertilisation of the season to prepare your green space for the new gardening season. Aim to scarify your lawn in October or November, because the soil recovers very quickly at that time of year.
When should I scarify my lawn for the first time? It usually takes three years before a freshly laid lawn achieves sufficient growth and hardiness for scarifying – any sooner and there is a risk of damaging the young grass roots. Only if your new lawn has grown particularly thickly might lawn scarification be appropriate as early as in the second year.
Scarifying in autumn
Although scarification and aeration of your lawn helps control stubborn weeds and matted moss, it also puts a lot of stress on the soil; this is why any late-summer lawn scarifying should certainly be done with a lighter touch. Your lawn needs a chance to recover well so it can enter its winter dormancy with renewed strength.
When not to scarify
- Avoid scarifying your lawn at the height of summer or when it’s very hot.
- If it’s raining or the soil is very wet, wait for conditions to change before you scarify – sodden, heavy soil is not easy to work with and will not aerate as you want it to.
How often do I need to scarify my lawn?
A strongly growing lawn with no matted thatch does not necessarily need to be scarified; simply raking through to dislodge any dead grass is sufficient. If you do have matting or moss growth in your grass, you should scarify your lawn twice a year at most.
How to scarify a lawn
Scarifiers have very sharp blades, and before you actually get going it’s important to make sure they are correctly adjusted. If you scarify with the blades in the wrong position, you can badly damage your lawn.
Set the depth of your scarifier correctly
The right working depth to scarify at depends on the age of the lawn and the extent of matting. As a rule, the blades should not rip the ground open, but rather just lightly skim the soil. Keeping that in mind, adjust the blades so that they penetrate the ground to two to three millimetres, testing the depth on a small section of the lawn and readjusting if necessary. A very neglected lawn may even handle four millimetres, but to avoid permanent damage you should never scarify grass more deeply than that.
Scarifying: step by step
- Before scarifying, mow the lawn to a height of around 2 to 3 cm.
- Adjust the scarifying blades to the correct depth.
- Be sure to not scarify too deeply.
- Start by evenly working over the whole lawn in one direction, then turn 90 degrees and go across the whole area again.
- Move quickly and evenly over the lawn without pausing, to ensure that you do not damage the turf.
- Make sure there are no large stones in the path of the scarifier.
- If you are using a tool without a grass catcher box, remove the loosened thatch with a rake.
After scarifying
When you’ve finished scarifying your lawn may look a little less attractive at first, but before long your efforts will be rewarded with lusher, more beautiful grass. A good lawn care tip is to apply sand or fine compost and fertiliser to your lawn after you scarify it; overseeding is only necessary if there are larger bare patches of lawn.
Scarifying tools
In return for regular care and removal of moss, weeds and thatch, your lawn will reward you with strong, beautiful green growth. Let one of our cordless battery or petrol-driven lawn scarifiers make your task much easier – you will particularly feel the benefit if you have heavy soil or a lot of thatch in your lawn. Manual lawn scarification tools are also available if you are willing to put in some extra work.
How does a scarifier work?
Scarifying tools have rotating blades that penetrate through the lawn and a few millimetres into the ground below, aerating the soil as they pass through and facilitating the easy removal of weeds and intruding roots.
Selecting the right scarifier
You can easily scarify small areas of lawn with a manual scarifier, but if you need to scarify larger areas we recommend you get some extra power behind you: a STIHL cordless battery or petrol-driven scarifier will make easy work of clearing thatch and invigorating your soil.
Electric or petrol-driven scarifier? An electric scarifier from STIHL is ideal if the lawn areas you need to scarify are close to your house, where a power outlet is available. If you need to work a little further afield, a STIHL scarifier with its own powerful battery or petrol engine are also available.
The advantages of electric and petrol-driven scarifiers
- Saves time and energy Even if you have heavy clay, very dry soil or a large expanse of grass, these tools help you tackle a labour-intensive task quickly and efficiently.
- Consistent working depth The precisely adjustable blades ensure that your lawn is scarified evenly, smoothly and gently.
- Quick and effective Battery Lawn Mower, even large lawns can be aerated in a single pass with ease.
