The Best Lawn Aerator

Written by Daniel Woodley. Reviewed by Elizabeth Smith. Published to Lawn Care on 6th February 2020. Updated: 22nd February 2023.

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Lawn aeration is an important part of maintaining strong and healthy grass, but it’s easy to get it wrong and damage the lawn.

I’ve seen first-hand how after years of lawn growth and compaction from foot traffic, the soil can become so hardened that the grass’s roots struggle to grow.

With poor root development, nutrient uptake is reduced, the grass is weakened, and from my experience, the outcome is usually a lawn far below its potential.

Not every lawn requires frequent aeration, it all depends on the level of compaction, soil type and how much thatch and other matter has been allowed to remain in the grass and for how long.

My advice below is based on my 18 years of experience, and I’ve aerated lawns dozens of times.

Lawn Aerator Tools – Your 2 Options

When it comes to using a lawn aerator, you have two types of tool to choose from.

Other professionals and I will typically use a motorised plugger; this is a type of aerator that digs out small plugs of lawn, around 70mm deep and 15mm or so in diameter.

However, I’ve seen gardeners use tools with spikes more recently, even though I feel they offer little benefit to the average garden.

The images below help to explain what these tools look like and how they work:

1) Lawn Pluggers

A closeup showing the plug remover machine

These machines are perfect for professional use, but given the price tag, they’re rarely purchased by gardeners for domestic use.

If you have a large or even a medium size garden, you can hire these pluggers, and many outlets offer delivery and pick-up services. I even know quite a few gardeners who don’t own one of these, but they hire them often.

For smaller gardens, I’ve found a manual plugger works just as well, but it does involve some hard work.

I’ve used the Walensee coring aerator several times and it was one of the best garden tools I’ve tested (see my review here), it’s very well built (solid steel) and it ejected the cores onto the lawn, ready for me to rake them up:

Removed plugs

2) Spikes

Another spike lawn aerator tool

Spike rollers and manual tools, similar to a garden fork, are the most commonly used tools among amateur gardeners.

I’m not a fan of shoe spikes or spikes in general as I tried them, and I found they didn’t dig very deep into the soil and the spikes were woefully thin.

Also, with every step I took, I found I was compacting the ground even more due to my weight pressing down on the grass, so I feel these products are counterintuitive.

There is a noticeable difference between how pluggers and spikes function; spikes do not remove any grass, instead, they compact the lawn horizontally as they’re pressed into the ground.

Pluggers and coring tools remove a small section of grass without any compaction and are more effective at aeration, in my opinion.

A closeup showing shoe with thin spikes

A light and well aerated soil.

When is the Best Time of Year to Aerate a Lawn?

The entire point of lawn aeration is to help with drainage and to encourage root growth, so the grass becomes stronger and healthier through deeper roots and increased nutrient uptake.

Grass typically doesn’t grow much when the temperature drops below 5 degrees, and during the height of the summer, it may go dormant.

I have always avoided aerating a lawn during the weather extremes of winter and hot summers.

I feel that the best time to aerate any lawn is in one of the growing seasons – springtime or autumn. If I had to choose between them, I would suggest scarifying the lawn lightly in the spring and overseeding any bare patches and then, in the autumn, aerating it with a plugger. 

How Many Times a Year Should a Lawn Be Aerated?

I have seen first-hand how lawns have improved dramatically with just a yearly aeration using a plugger/coring tool, but given how invasive they are, I don’t think you should use them more than once a year unless your lawn gets a ton of foot traffic and is very compacted.

I do believe that the average domestic can benefit from the occasional aeration, so I suggest most gardeners aerate their lawns no more than once a year or once every two years if the ground isn’t hard.

I read an article a few years ago where The Royal Horticultural Society recommended aerating domestic lawns no more than once every few years but I can’t locate the guide.

What’s the Difference Between Sacrifying and Aerating?

As a lawn matures, cuttings, tiny leaves and twigs, weeds and other decaying organic matter collect in the grass.

This material is known as thatch.

A small amount of thatch can be beneficial, it breaks down into a fine matter rich in nutrients that feeds the grass.

However, I’ve seen that excessive amounts of thatch:

• block sunlight which is crucial for grass blade and root growth
• stop the roots from getting oxygen
• acts as a water barrier, soaking up moisture and causing the soil underneath to dry out

Dethatching, also known as scarifying, is a process where the excess thatch is raked out and removed from the lawn. This is something I have done many times, and I suggest gardeners do this once a year as it can really help to let the lawn breathe.

Aerating focuses more on the soil, allowing more moisture and oxygen to get to the root area, where it encourages root growth and nutrient uptake.

Both processes can be tackled simultaneously, although I’ve seen gardeners choose to scarify in the spring and aerate in the autumn or vice versa; in my opinion, it really doesn’t matter.

How often you scarify and aerate depends on the lawn, its growth rate, levels of thatch and compaction etc., but I’m sure that once a year for both would be a good starting point.

Can a Lawn Be Damaged By Excessive Aeration?

Yes.

I saw my own neighbour damage his lawn by walking over it several times with lawn shoes (with spikes), he ended up with a more compacted lawn, and it did nothing to improve aeration or drainage.

I’ve also seen lawn aeration tools used excessively in shaded gardens where the lack of sunlight meant the grass took longer to recover.

If you’re struggling to establish a lawn in a shaded garden, my in-depth guide to growing grass in shade is an excellent read where I reveal practical solutions that actually work, such as moss control, advice on iron sulphate and other products such as bacteria that eats lawn moss, etc.

I 100% recommend lawn aeration, but I don’t see the need to do it more than once a year, and in my opinion, it will benefit lawns that are hard and compacted the most.

As for drainage, it can help speed up surface drainage, but if the lawn is constantly boggy or under an inch of water when it rains, you’ll probably need a more drastic solution, like a French drain or similar.

HOW TO GROW GRASS IN A SHADED GARDEN

Quite possibly the most in-depth and comprehensive guide to growing a grass lawn in shade you will ever read. Start Here