When Should I Aerate My Lawn?

Aeration is the process of perforating soil to allow air, water and nutrients to reach the roots of your lawn.

This ensures strong roots which can grow deeper and support more vigorously growing grass, and can stimulate the activity of beneficial soil microbes.

It’s something you can do yourself or, if you have a large area and not enough time, you could hire a professional lawn care service to take care of it for you.

Carried out regularly, aeration can protect your lawn against common problems, such as soil compaction, poor drainage, bare patches, excessive thatching and weed outbreaks.

Aeration is an important tool for helping your lawn recover after significant rain.

It’s also recommended during prolonged dry conditions and drought to make it easier for limited rain and water – especially if you have water restrictions – to reach the root zone.

Your lawn also would benefit from aeration if:

• It gets heavy use from children and pets.
• It was established as part of a new home build – the topsoil of new lawn is often stripped or buried, and the subsoil compacted by construction traffic.
• It dries out very easily and has a spongy feel underfoot. This often indicates excessive thatching. Aeration is recommended when the layer of thatch is greater than 1.5cm.
• Your lawn is newly established, because it may have a layer of finer textured soil over the existing coarser soil. This layering can disrupt airflow and drainage to the newly developing roots.
• It has become compacted over winter.

The best time to aerate your lawn is during the growing season, when the grass can quickly fill in any open spots after soil plugs or cores are removed.

Ideally cool season grasses, such as Ryegrass, Fescues, Bluegrass and Bentgrass, would be aerated in early spring or autumn, and warm season grasses, such as Buffalos, Zoysias, Couch and Kikuyu, in late spring.

How Often to Aerate?

Clay-based soils and those containing low levels of organic matter are more prone to compaction.

There’s a guide to softening hard lawns here.

If your lawn experiences only minor compaction, it’s worth aerating at least once a year. Badly compacted lawns on clay soil will require more frequent aeration and may need thorough renovation to bring them up to scratch.

Signs of compaction can include:

• Pooled water at the surface.
• Shallow roots.
• Slow growth and reduced tillering.
• Yellowing of leaf blades.
• Thinning of grass.

Appearance of weeds that are more tolerant of waterlogging, such as Carrot Weed and Nut Grass.

Aeration involves using spikes or coring machines to punch holes in your lawn and remove chunks of grass and dirt.

This can be done manually with a garden fork or specialised tools, or using a motorised implement or attachment towed behind a ride-on mower or tractor for large areas.

When choosing a tool or machine, aim for one that removes soil plugs about 5cm deep and 2cm across.

Lawn Aeration Tools

1. Aerator shoes or sandals

Available from most hardware or garden centres, these are usually one size fits all and strap on over your shoes or boots. You can then walk around your yard – remember to lift your knees high to avoid tripping over – and the spikes will put small holes in your lawn.

2. Long handled aerator forks

These have a long handle attached to a bar you can step on to push them into the ground. They can have tynes, spikes or hollow prongs that remove a plug of grass and soil.

3. Rolling lawn aerator

For people with mobility issues, these are easier to use than aerator sandals, but they’re often lightweight don’t last very long, and models with plastic wheels are suitable only for use on very sandy soil.

4. Motorised mechanical aerators

Self-propelled machines you walk behind like a home lawn mower, these are better and faster at producing holes in your lawn. They range from electric and battery powered models to petrol and even stand on machines.

Some claim to be able to cover a 1000 square metre block in as little as 15 minutes.

Needless to say prices vary from several hundred dollars to more than $7000, depending on how many bells and whistles are included. Some machines are available for hire.

Step-by-step Guide to Aerating Your Lawn

1. Mow or dethatch your lawn, if the layer is thicker than 12mm. Excessive thatch will make your lawn feel spongy underfoot and increase the likelihood of waterlogging and fungal disease. There’s information about how to dethatch a lawn here.
2. Before you start aerating – either with a tool or machine – make sure the soil under your lawn is moist but not saturated. It is advisable to aerate a day or two after rain or watering your lawn.
3. If you have irrigation pipes under the lawn for pop ups or sprinklers, make a note or use markers to highlight their location and depth to ensure you don’t puncture or break them.
4. When manually aerating with aeration sandals or a fork, aim for a 10cm gap between holes. It might be necessary to go over some heavily compacted areas twice, from different directions.
5. Allow the excavated soil plugs to dry out and then break them up with a rake or run over them with a mower. Be sure to sharpen your mower blades after breaking up the plugs.
6. Fertilise within 48 hours and ensure the fertiliser is thoroughly watered in. There’s a guide to fertilising your lawn here.
7. Top dress about a week after fertilising and two weeks after aeration to address unevenness or bare patches and boost organic matter levels. There’s a guide to topdressing your lawn here.
8. Repeat the process each spring, or more often if needed.

Extra Tips

• Especially if you’re hiring a machine, save time, energy and money by leaving uncompacted areas alone.

Test pH and apply soil additives or conditioners such as lime or gypsum, if needed.
Lime helps neutralise acid soils – the ideal pH range for most lawn grasses is 6-7 – and gypsum helps break down clay soils, making them less prone to compaction, more porous and better able to absorb moisture. There’s a guide to using gypsum here.

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Lawn Pride Maintain 26-1-9 + 3.4 Fe 20kg

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OxaFert 16-2-6 20kg

Remember – aeration is a beneficial practice for achieving a beautiful lawn, but many people don’t understand the process.

Make aeration part of your regular lawn care regime and your grass will thank you for letting it breathe again.

You can also browse a range of leading brand name lawn care products at myhomeTURF’s online store.