How to Aerate your Lawn

The Complete Guide to Aeration

Let's start with the basics: Why Aerate?

Plant roots need oxygen much like we do. Most people understand that plants give off oxygen, but this is only in the green areas of the plant.

The rest of the plant still needs oxygen for the same reason as we do. We need to ensure our soil is loose enough to give our plant’s root system sufficient air. This is the process of aeration. The purpose of this guide is to make sure you know why and how you can aerate your garden and lawn.

Let’s look at some of the benefits of aeration:

• Encourages new root growth
• Increases the roots depth
• Improves nutrient uptake
• Reduces thatch build up
• Improve infiltration rate of water into soil
• Improves drainage

When should we Aerate?

Lawns can generally be aerated at any time. But for the best results you will need to check the preferred times below. These times depend on the type of grass you have.

The two major types of lawns in New Zealand would be Fescue and Rye grass, which can be done in late summer to early spring. Another grass which is common in some areas is kikuyu. This warm season grass can be aerated mid to late spring.

Your garden should be aerated regularly. Especially prior to new planting.

How often should you Aerate?

Lawns should be aerated once a year.

Aerating twice a year for clay soils is ideal as they are a lot denser than sandy soils and have water absorption problems.

Equipment for Aerating

Firstly we’ll look at lawns, they take more equipment that garden beds do.

There are two main tools to use to aerate; a spike aerator (left) or a plug/core aerator (right). 

The difference is that the spike aerator pushes holes in the ground whilst the plug aerator makes holes by pulling out small parts of the soil.

The plug aerator is preferred as it creates more space in your soil, by actually removing small holes throughout the lawn.

Both should be available from your local hire shop, when given a choice use a plug aerator.

If you have a smaller lawn you can use a garden fork of aerating shoes. These generally take longer but are a more affordable option.

For your garden you can use a hand tiller or garden fork.

How to Aerate

Aerating a garden bed:

It’s quite a simple process. The soil simply needs to be turned over. This can be done by using a hand tiller, and pushing through the soil to loosen. Alternatively, you can use a fork to pick up and turn the soil.

Be careful to avoid making contact with plant roots.

Aerating your lawn:

Before aerating, there needs to be some preparation done to your lawn.

Often dethatching your lawn can be done at a similar time, you may want to do this prior to aeration. The soil also needs to be moist so water a day before aerating. You could also choose to wait a day or two after it’s rained.

Prior to aeration, mow the lawn. Make sure you use a catcher.

You will want to make holes in your lawn around 10 cm apart. If you using a core aerator set it to pull out cores that are 3 inches long. Your hire shop should show you how this is done. These cores can often be left on the lawn to top dress, alternatively you can rake them up and remove them.

To ensure you don’t miss any spots, run the aerator over the lawn a second time perpendicular to the first run. Using a fork or aerating shoes is fairly simple. You basically plug holes throughout the lawn, much like mowing a lawn ensure you don’t miss any spots.

Water your lawn following aeration.

You may like to consider top dressing after dethatching and aerating.

If there’s anything you’ve missed, this video might fill you in.