Aerating your lawn – how to help your lawn to breathe again
Spiking, dethatching or aerating? Our guide will explain the right measures to ensure a well-aerated lawn.
13.11.2024
Overview: Aerating the lawn
- Note the difference between dethatching a lawn (removing surface moss and matting), aerating (improving the soil’s access to air) and scarifying; the distinction is in how the respective machines work the lawn or soil.
- While a dethatcher has flexible prongs which comb through the lawn superficially, scarifiers uses rigid blades to cut through the turf and slightly open up the ground. In contrast to these two approaches, in core aeration deep holes are punched into the ground, spiking the lawn.
- Core aeration is mainly used on golf courses and in football stadiums, and will not generally be necessary in your own garden. Instead you should opt for a lawn aerator with a dethatching comb roller.
- Although a lawn aerator doesn’t do the job of a scarifier, regular aeration reduces the need for this strenuous treatment.
You can use a lawn scarifier such as the STIHL RLA 240 to aerate your lawn for the first time from November at the latest. We recommend regular use to remove thatch, moss and weeds from your lawn; doing so will give the lawn air and also ensure that it can better access the nutrients it needs from the soil.
As a preparatory measure, you should mow your lawn before aerating.
We recommend that you aerate your lawn every four to six weeks from spring to autumn, whereas you should scarify no more than twice a year because the procedure is very stressful for your lawn.
Yes, you can scarify or aerate your lawn in Autumn. We recommend scarifying your lawn in the Spring, but if necessary you can also carry out or repeat this measure in the autumn. However, you should never scarify more than twice a year.
Why should aerate a lawn?
Like all plants, your lawn needs sufficient air and water to feel comfortable and supply the nutrients it needs for healthy growth.
A key sign to a stressed lawn is compacted soil menaing supply of air to your lawn is limited. The micro-organisms in the soil become sluggish and cannot break down cuttings and dead grass as efficiently. This causes matted lawn thatch to form. The weakened lawn can no longer defend itself against moss and other grass problems, and the lush green is replaced with an unsightly yellow or brown.
To avoid this, we recommend including lawn aeration in your regular lawn care. If you have very dense, clay-rich soil in your garden, you should also sand the lawn as an additional measure.
Know your terms: dethatching, scarifying and aerating a lawn
Is your garden exhibiting any of the symptoms mentioned above or do you want to prevent the formation of thatch by regularly aerating your lawn? You might soon get into a muddle when searching for tips and tricks in books or on the internet, because some guides use different terms interchangeably – though they are actually distinct from each other.
Core aeration or aeration? Dethatching, scarifying or aerating? To make sure you don’t get lost in the jungle of technical terms, we will outline the most important differences, tell you when to aerate the lawn and explain which measure is the right one for your garden.
Remember: core aeration for lawns is not the same as aeration
When trying to find out how to aerate your lawn, you will often come across descriptions of core aeration. Although this is sometimes simply referred to as “aeration”, it is actually a specific process of its own.
In core aeration, a spiked roller punches deep holes into the ground, which are then filled with sand. This measure is used primarily on golf courses and in football stadiums, to ensure a lush green lawn that looks great on television and remains playable even in wet conditions.
Core aeration is not usually necessary in your garden. The only situation in which it may be practical to punch holes in some areas of your lawn is if you are sanding it to counteract very clay-rich soil. In private gardens it is usually sufficient to simply use a digging fork to pierce the soil in a few places. The use of an aerator roller is only necessary in extreme cases.
Instead, we recommend that you open up your lawn to air by using a dethatcher.
Dethatching also uses a roller, but not one that punches holes in the ground like the core aerating roller. Instead, it has flexible sprung tines which comb excess moss and other unwanted material out of the lawn without damaging the earth below.
The difference between aerating and scarifying the lawn
Lawn aerators and scarifiers are very similar in terms of how they operate. However, while a dethatching roller only combs through the lawn with its springy prongs, rigid scarifying blades are set deeper and slightly penetrate the soil below the grass. This means they remove and chop up thatch, moss and old grass cuttings with great efficiency.
Although this procedure is more thorough than lawn aeration, it also puts more strain on your lawn. Afterwards, it is often necessary to repair particularly stressed parts of the lawn by reseeding . You should therefore scarify your lawn no more than twice a year. We have put together some more information about scarifying for you in our handy guide.
STIHL tip: Lawn aeration tools such as the STIHL RLA 240 battery lawn scarifier can be equipped with a scarifying unit or an aeration roller.
A lawn aerator cannot completely replace the scarifier in your garden. However, if you aerate your lawn regularly, fertilise it with organic fertiliser, mow it properly and ensure that it is sufficiently watered, stressful scarifying can generally be reduced to once every two years – and your lawn will also look less battered afterwards.
How to aerATE the lawn: when and how often?
Unlike scarifying, you can and should aerate your lawn several times a year. The best time to do this is from November, after you have completed your initial spring lawn maintenance measures such as spring fertilisation and the first cut of the grass. You should repeat the procedure every four to six weeks until March before preparing your lawn for the winter break in autumn.
Lawn aerator: What tools can I use to ventilate my lawn?
You can enjoy the best of both worlds with the STIHL RLA 240 battery lawn scarifier in just a few simple steps, you can conveniently replace the dethatching roller with a scarifying unit on both models.
Aerating lawns with the STIHL RLA 240 battery lawn scarifier
Below we will show you how to aerate your lawn using the STIHL RLA 240 battery lawn scarifier. If you have another tool, you can simply skip the steps that apply only to the RLA 240.
If necessary, you should first remove any accumulated branches, pine cones or other coarser objects from your lawn. Then mow the lawn to prepare it for the next procedure. Make sure that the blades of grass are not too long.
The RLA 240 is a combination tool. To aerate the lawn, you can replace the built-in scarifying unit with the aerating roller in just a few simple steps. For your own safety, please observe the information provided in the operating instructions and make sure that you wear the correct protective clothing such as protective gloves and safety glasses.
Now attach the collection box to the rear of the tool. Aeration produces significantly less waste material than scarifying, especially if it is done regularly. Thanks to its 50-litre grass collection box, the STIHL RLA 240 allows you to conveniently collect remnants, saving the hassle of raking them up when your work is complete.
Now run the lawn aerator over the grass evenly in rows. Make sure that the tracks overlap slightly as you push the aerator along. For rectangular areas, you can simply go up and down the lawn before travelling along each end parallel to the edge.
Lift the tool slightly when turning – thanks to smooth-running wheels and a working width of 34 centimetres, the STIHL RLA 240 is particularly manoeuvrable even on angled surfaces.
Note: It is normal for some blades of grass to be visibly protruding after the lawn has been ventilated. If you find this bothersome, you can simply mow the affected areas again.
Once you’ve finished or the grass collection box is full, you can empty the contents into your compost bin so that the thatch you have removed can be reused sustainably.
Your lawn does not necessarily need to be fertilised after aeration, but if it’s time to fertilise your lawn anyway, we recommend that you do so after aeration. Ensure you water the lawn adequately when you have finished.
Caution: If you decide to scarify your lawn instead of aerating it, you should fertilise the lawn about two weeks in advance to prepare it for the stressful treatment.