Lawn Aeration

What is lawn aeration?

Lawn aeration is the process of making ventilation holes in your lawn which can dramatically improve its health and hence appearance. Done properly it has three main actions

Reduces compaction
Increases aeration
Reduces thatch

Why would I want to aerate my lawn?

You may want to consider aerating your lawn if you want a lawn that is

Is more drought resistance

Reducing soil compaction encourages deep roots which helps during periods of hot weather

Has thick, weed free grass

Reduces the amount of thatch in the lawn which inhibits grass growth and encourage disease

Needs less watering

Good drainage deeper into the soil means less of it is lost through evaporation/transevaporation.

Generally lush and healthy

Opening holes into the roots and soil allows oxygen to enter (and releases waste gas build up). This improves the health of the root system and grass overall.

If the lawn is walked on or generally used a lot then the underlying soil can become compacted.

Do I need to aerate my lawn?

A better question is under what circumstances is lawn aeration a bad or unnecessary idea? Your lawn will not need aerating if it is

A new lawn (either sown or turf) will not need nor desire aeration in its first year.
Hardly ever walked on or used and you are not in a heavy clay soil environment (which is more likely to become compacted).
If you live in a light sandy soil area you may not need to aerate your soil - though there may still be some benefit.

So when should I aerate my lawn?

Although expert opinion is that Autumn is the best time it can be done any time of the year. A more important consideration is whether the lawn/ground is too dry or wet. If its too wet any holes you make in the ground can re-seal. If it is too dry then making the holes becomes very hard work and may damage the tools you use! Ideally you are looking for a moist surface and so if the lawn is too dry/hard then give it a good watering a day or so before to soften it up.

How often should I do it?

Depends on the type of soil and how much use the lawn gets. Lightly used lawns may only need it done every couple of years whilst once a year is a good target for a heavy use lawn.

Equipment: Lawn Aerators

You are trying to lessen the compaction of the soil. This can be done by either

Lifting the soil/turf with a fork or
Removing a core/plug of soil from the lawn.

To do this you can either use a manual or powered tool

Manual aerators

Garden fork around £10+
Hollow tined fork aerator around £15+
Manually pushed roller with tines on (this will not lessen compaction) around £20+
Shoes with spikes on (as above) around £10

Powered aerators

Electric lawn aerator are about £125+ to buy
Petrol powered lawn aerators are about £200+ to buy and £50 per day to hire.

Note: I found that some places may do better deals if you require to hire both an aerator and scarifier.

How do you aerate your lawn?

Walk up and down the lawn in straight lines as you would when mowing it.
You are aiming for a uniform grid spacing about 10-15cm apart and to push the tines at least 10cm deep.
With a solid tined fork in order to reduce the soil compaction you must pull back on the handle when the tines are in the ground. This will lift the soil and turf slightly. Note you are NOT digging here!
A hollow tined aerator will pull a plug of soil out of the ground when you pull the tines out. This plug will be pushed out of the tines on the next set of holes you make.

Any aftercare required?

To prevent the holes from refilling you can apply a top dressing of a light sand/soil mixture. This will improve the overall drainage of the lawn. If this is combined with a slow release feed then it will ensure good penetration of the feed into the root system giving a good chance of a healthy lawn.