Aeration is a key way to maintain your lawn’s health because, as with all plants, air is needed around the roots for the plant to function properly. This is because:
- Air in between the soil particles allows the ground to retain water, giving a steady supply so your lawn can grow
- Air near the roots also gives the roots room to grow deeper in the ground, giving them access to more nutrients and giving you a more resilient and healthy lawn
- Proper aeration reduces the buildup of thatch in your lawn. Thatch is dead grass that builds up on top of the soil. Air in the ground encourages aerobic bacteria to decompose the thatch, recycling the nutrients back into your soil. If there isn’t enough air, the thatch builds up and anaerobic organisms grow in it, leading to disease
- Aeration also encourages a denser grass coverage, leaving less room for moss
As time goes by, gravity and your footsteps gradually press the soil down, reducing the air in the ground. You can reverse this process by aerating your lawn, either just focusing on areas of high use or aerating the whole of the lawn area.
You can aerate your lawn either by using something that takes cores from your lawn (a hollow tine aerator), something that uses spikes (a spiked aerator), or something that makes small cuts in your lawn (a chisel aerator)- there are a variety of tools that do this:
- A manual hollow tine aerator fork
- A manual spiked aerator roller
- Spiked aerator shoes
- A hollow tine machine aerator
- A spiked aerator machine
- A chisel tine aerator machine
In terms of when you aerate your lawn, you should be looking to do it once every year – if your soil is mostly clay it may need to be done more often. You should wait for a year before aerating newly seeded lawns.
Autumn and Spring are good times to aerate, as the best time to aerate your lawn is when the ground is moist-not too dry and not too wet. You can water your lawn the day before to make sure there’s enough moisture in the ground to make penetrating it easy. It will also make the job easier if your grass is cut fairly short. Make sure you mark out any wires or sprinkler heads in your lawn beforehand, as an aerator will damage them.
If you’re using a manual Hollow Tine Aerator, or something with spikes, go over your lawn as many times as you think necessary. With a manual Hollow Tine Aerator you should be aiming for the holes to be about 2 inches apart.
If you’re cutting into the lawn with a Chisel Aerator or using a hollow tine machine, go over your lawn in one direction only-that should be enough.
If you use a Hollow Tine Aerator, try not to roll over the cores with your aerator or tread on them, as this will make them harder to move. The cores won’t rot down by themselves, so don’t just leave them there. The best thing to do with the cores is to let them dry where they are, and to then mow them using your lawnmower with the box taken off.
This is a messy job, and may produce a lot of dust, so wear old clothing, protect your eyes and mouth and close any windows facing your garden. If you want to remove the cores, the best thing to use for this is a dummy rake, which is a rake with a single blade across it rather than spokes.
If you’ve got any bare patches in your grass, post aeration is a great time to sow some more seed – it’ll take a lot more easily.
Aeration should improve your lawn’s health immediately, but it may take some time to see visible results, so be patient!