Your grass needs space below ground to take in air, nutrients, and water. This is what we mean when we say your lawn’s roots need to ‘breathe’.
Aerating your lawn and allowing it to breathe benefits you in many ways. A healthy lawn can drop the temperature of your home’s surrounds, creating a pleasant environment and saving on energy costs. But aerating also helps to protect your lawn against all the problems that go along with compaction: drainage issues, bare patches, weeds, dryness, fungal disease, fairy rings… the list goes on! Let’s look at how you can use aeration to keep your lawn looking its best.
What is aeration?
Aeration is perforation of the soil to allow air, water, and nutrients to penetrate the grass roots. Aerating is often overlooked, but its importance cannot be overstated.
Why do I need to aerate my lawn?
The main reason for aerating is to alleviate soil compaction. Soil compaction limits the amount of nutrients and water that can penetrate the roots of your lawn. Conversely, aeration helps the roots grow deeply and produces a stronger, more vigorous lawn.
How do I aerate my lawn?
A small area of lawn can be aerated manually with aerating sandals, which have spikes that aerate the lawn as you walk. Alternatively, a sturdy garden fork will do the job. Simply insert the fork into the lawn and wriggle it back and forth to fracture the soil profile. Repeat this across the lawn with a spacing of around 8–10 cm. Depending how compacted the soil is, you may need to go over the area twice in different directions to achieve adequate aeration.
If you have a large lawn, you can hire a specialised aerator. Rather than just punching holes in the ground, plug aerators actually remove plugs of soil from the lawn in a process known as ‘core aeration’. This not only relieves compaction more effectively than regular aeration, it also provides space for lime, gypsum, or coarse sand to be incorporated into the profile in order to improve drainage or pH.
How often should I aerate my lawn?
Different soil types require different frequencies of aeration. Clay soil compacts easily and should be aerated at least once a year, while a sandy lawn only needs to be aerated every 1–2 years. In harsher climates, aerating twice a year will encourage better turf growth and health.
Compaction is common in areas where there is high foot traffic, pets, or even cars on the lawn. Regular aeration will be important to help the soil to breathe and the grass to spread, and to ensure the ground doesn’t become too hard.
When should I aerate?
The best time to aerate warm-season grasses, such as soft-leaf buffalo, couch, kikuyu, and zoysia, is during spring and summer while they are actively growing. You can aerate at any time of year, but if you do so in the cooler months just keep in mind that the grass will be dormant so it won’t cover over the holes.
For cool-season lawns, such as fescue or rye grass, the same principle applies. Except in very cold climates, cool-season lawns can grow all year with proper care, so you can aerate all year round.
For all lawn types, you should always try to aerate at the same time as fertilising, dethatching, top dressing, or any other major lawn care operation. Aerating is easier in moist soil, so after rainfall is a fantastic time for aeration.
Test your pH
Soil pH affects your lawn’s ability to absorb the minerals and nutrients it needs in order to thrive. After aerating is a good time to test your pH and take action if required, as the aeration provides the perfect environment for penetration and absorption of soil additives.
The ideal pH range for your lawn is 6 to 7. If your pH is outside this range, now is also the time to remedy it with soil additives and conditioners: