Aeration is an important yet often overlooked aspect of lawn care that can restore a ragged lawn to its former glory and help it thrive. And to help, here’s our guide to how to aerate a lawn to give you all the information you need.
For a video of some of the stuff we’re going to be talking about, check out this video before reading on.
What is aeration and why do we need to do it?
Aeration is the practice of making small holes in your lawn to help air and water penetrate the ground and reach the roots of your grass, helping the roots grow strong and deep and maintaining the overall health of your lawn.
While most people understand that things like mowing, watering and even overseeding should be incorporated into the annual cycle of lawn care, aeration is often neglected. This is despite the fact that it is just as important as many other aspects of looking after your lawn.
With time and use, lawns become compacted. This is when the soil becomes hardened, and when this happens, water is unable to reach the roots. Instead, it may simply sit on the surface in puddles until it evaporates.
At the same time, oxygen is unable to penetrate the ground, and roots also have a harder time growing in compacted soil, leaving your grass less prepared to deal with periods of stress like drought.
Another reason to aerate a lawn is to help with thatch, a layer of dead organic matter lying on the surface below the grass. This is a different issue to compaction, but the result is similar since water and oxygen are less able to penetrate thatch to reach the roots of your grass.
When thatch begins to build up, the best solution is to scarify your lawn to remove it, but this can be combined with aeration for the best results.
To check if a lawn needs aeration, push a screwdriver into the soil. If you meet resistance, it is a good sign that aeration is necessary.
What causes compaction and thatch?
Compaction is a natural process that occurs in a lawn with use. People walking or playing on the lawn will cause it to become compacted, as will the use of machinery such as lawnmowers or anything similar.
Certain areas may become compacted more quickly than others – for example, an area that is commonly used as a football pitch will become compacted more rapidly, as will an area where you often walk to hang up washing.
Thatch is also a natural occurrence – and a thin layer of thatch in your lawn is considered healthy. However, with time, it will become thicker as grass clippings and other organic material accumulates, and when it becomes thicker than 1cm, it can start causing problems.
When should you aerate your lawn?
If your lawn sees heavy traffic, perhaps with children or pets playing on it, for family barbecues or any other reason, this may cause it to become compacted, in which case, aeration will be necessary.
The lawn of a newly-built house will almost certainly need aerating since it will probably have experienced heavy traffic during construction, leading to compaction.
Furthermore, any lawn that seems excessively hard or that tends to dry out quickly will probably benefit from aeration.
Conversely, if your lawn seems spongy and soft, it is probably beginning to develop a thick layer of thatch, in which case, aeration and scarification will also be beneficial.
You can aerate a lawn at almost any time of year – the main times to avoid are when the lawn is wet just after rainfall or frozen after a frost. Aerating very dry soil is also best avoided.
However, if it is possible to choose when to aerate your lawn, the best time to pick is just before the growing season in early spring or at the end of summer.
This is because it will help deliver water and oxygen to the roots, stimulating their growth and allowing them to push down into the soil, establishing a deep and healthy root system.
Generally speaking, you should consider aerating your lawn at least once a year to combat compaction. However, some gardeners claim that giving your lawn a light aeration as often as every month can have significant benefits.
Different aeration methods
There are several different techniques for aerating a lawn, and they can be divided into those using solid tines, those using hollow tines and those using chisel or slicing methods.
Solid tine methods are no more complicated than poking a series of holes in your lawn. This can be done manually with a standard garden fork or by putting on special aeration shoes with spikes on the soles and walking around on your lawn while wearing them.
For larger areas, machines also exist that can spike holes into your soil.
Using solid tines is the simplest method, but some gardeners suggest that this can even contribute to increased compaction in the long-term as the holes fill in and the ground becomes even more solid.
Alternatively, using a hollow-tine aerator removes plugs of soil from your lawn, leaving larger holes in the ground and allowing more oxygen and water to reach the roots.
Here’s a video showing you how to do this with a machine.
These plugs can then be smashed manually or mown over, returning the nutrients to the soil.
Using a machine that slices your lawn is also becoming more popular since the larger surface area of the slices maximises the amount of water and oxygen that can penetrate the ground.
The best advice is probably to use a combination of these techniques, perhaps using a fork or aeration shoes to aerate your lawn lightly a couple of times a year – followed by a deeper aeration session using a hollow tine or chiselling machine once a year.
How to aerate a lawn
There are three parts to aerating a lawn – pre-aeration, the aerating itself and post-aeration. Let’s have a look at how to do it now.
Before aerating, it’s a good idea to scarify your lawn. You can do this either by using a rake to pull up the worst of the thatch or by using a dedicated scarification machine. Your choice will be determined by the extent of the thatch layer present in your lawn.
After scarifying, you should then give your lawn a close trim with the mower, especially if you are going to use a hollow tine aerator – this will make it easier to pick up or smash the plugs.
If you are using a fork, simply walk up and down your lawn, digging the fork into the soil to a depth of around 4-6cm at intervals of every 4-6cm. This is fine for smaller lawns, but for larger areas, it may be too time-consuming.
For larger areas, aerating shoes might be a better choice. To use them, you just need to strap them onto your shoes and walk up and down your lawn several times to achieve the desired effect.
If you are using a manual hollow tine tool, the process is the same, so just walk up and down pulling up plugs of lawn every 4-6cm. Here’s a video showing you how it’s done.
With a machine, either a hollow tine version or a chisel machine, simply push it up and down your lawn until you have covered the whole area.
After aerating your lawn, if you have used a hollow tine method, after they dry, you should either use a lawnmower to smash the plugs and return the nutrients to the ground or go round smashing them manually with a rake or spade.
This will also help stimulate bacterial activity, further boosting the health of your lawn.
However, you shouldn’t just leave them sitting on the top of your lawn since they won’t break down naturally and will just cause your lawn to become bumpy and uneven.
After aeration, also consider fertilising since the soil will be in the perfect condition to absorb the fertiliser.
Tips for success
Here are a couple of extra tips that will help you get the most from aerating your lawn.
- Focus on high-traffic areas
When aerating your lawn, focus on areas of high traffic to save yourself some work. Aerate the whole area once a year, but for the rest of the year, concentrate on the parts that become compacted quicker.
- Aerate before any major work
Always aerate before doing any major work on your lawn like reseeding, overseeding or laying turf. This will give the new lawn the best chance of becoming properly established.
- Use the fork-and-lift technique
If you are using a fork to aerate, each time you push the prongs into the ground, lift a little too. This will increase the effectiveness of the aeration.
- Aerate after rain
Aerating after rain will help save you some effort – although you shouldn’t aerate while your lawn is still sodden after heavy rain.
- Don’t aerate during a drought
Similarly, don’t aerate during a drought. It will be tough going, and the cracked ground will just crumble and harden anyway. Better to wait until there is a bit of rainfall before starting work.
A useful addition to your annual lawn care cycle
As you can see, aeration is a simple yet vital technique you can add to your annual lawn care cycle, helping the roots of your lawn grow strong and deep and contributing to the overall health of your lawn.