The Best Lawn Aerators (Manual and Machine)

Lawn Aerators
Although I mostly write about gardening, from time to time I like to touch on other yard-related activities…

Including the lawn. For some, the lawn is a staple of the yard, and proper lawn care is something to be sought after.

When thinking of lawn care, fertilizing, mowing, and edging come to mind. But aeration? Dethatching? These are less common practices that are absolutely vital to proper lawn care.

In this article, I’ll look at what aeration is, why it’s important, and which lawn aeration products are the best on the market.

If you’re just looking for the recommendations, here are the picks:

What is Aeration?

Lawn Aerator

An overview of the lawn aeration process. source

Let’s understand aeration before we get into how to do it. Lawns are notorious for becoming compacted over time. The dense matting of grass as well as constant foot traffic cause soil to become dense, making it harder for air, nutrients, and water to reach the roots of your lawn.

Aeration is one way to solve this problem. By punching little holes into the soil, you’re giving roots access to the essential resources they need (water, air, nutrition).

Dethatching vs. Aerating?

If you’re researching lawn aeration, chances are good you’ve come across the term “dethatching.” Before we define it, let’s define what “thatch” is in the first place. This is from a video from the Scotts company:

Thatch is dead roots, stems, and cells from your grass blades that have fallen down into the soil. It’s the layer that lives between your healthy grass and your native soil.

By itself, thatch is not a bad thing. In fact, up to about 1/2″ of thatch is actually good for your lawn, providing a barrier from the intense heat of the midday sun.

Any more than 1/2″ of thatch can be harmful though — it prevents the roots from establishing themselves by creating such a thick layer that your grass ends up rooting in the thatch layer instead of the soil.

If you simply have excess thatch on your lawn, you’re best served by dethatching instead of using a core aerator. However, most lawn owners have problems with both thatch and compaction, so they opt for aeration as it solves both problems at once.

Should You Even Aerate Your Lawn?

Contrary to what lawn care companies would have you believe, not all lawns are good candidates for aeration. Here’s a quick checklist to see if you need to aerate your lawn.

If your lawn..

Dries out easily or have a “springy” feel to it. If so, you may have more than 1/2″ of thatch. To find out, take a shovel and chop out a chunk of lawn at least 4-5″ deep. If you have more than 1/2″ of thatch, you should consider aeration.

Was constructed along with a new home. New homes often have extreme compaction on the lawn area due to the building process (large machinery, lots of people, etc.). You should consider aerating your lawn if you’ve purchased a new home.

Gets used often. The more your lawn is used, the more compacted the soil will be. If you have children, pets, or neighborhood gatherings often, chances are good that your lawn is compacted and needs aeration.

Was built out with sod and has layers of soil. If you lay down sod on top of existing soil, there’s often a mismatch in soil density. The sod has fine particles of soil, while your existing soil is often much rougher. Aerating lawns with these conditions helps to blend the layers together, making it easier for roots to establish themselves.

The Benefits of Aeration

Here’s a quick list of just some of the many benefits to aerating your lawn. Most of these apply to core aeration and not just dethatching:

  • Soil absorbs more water
  • Reduces soil compaction
  • Thatch breaks down easier
  • Lawn is more resistant to heat and drought stress
  • Oxygen uptake of soil increases
  • Stronger root development
  • Fertilizer and nutrients in soil are more easily used by grass
  • Water runoff decreases significantly

Pretty good list of benefits, eh?

The Best Time to Aerate Your Lawn

If your lawn qualifies for aeration, the next logical step is to ask when you should aerate.

As a general rule, you want to aerate when the grass is growing the fastest.

By aerating in the growing season, you allow roots time to re-establish themselves in new soil.

For warm-season grasses, aerate later in spring. For cool-season grasses, aerate in the beginning of spring.

How Often to Aerate Your Lawn

As a general rule, aerating once per year is a good idea. If your lawn gets used extremely often, you may want to aerate twice per year. As an example, golf courses often aerate 3-5 times per year. But they’re a special case — those are lawns that are designed to be walked on!

What to Expect After Aeration

After you aerate your lawn, it will look a bit odd. There will be plugs of dark soil littering the yard. This is natural — after a few weeks they break down and are reincorporated into the soil.

A week after aeration, you can peek into some of the holes that your lawn aeration machine created. If you see white roots, it means that your grass’ roots are getting the oxygen they need to develop.

Every time you aerate, you should see water retention on your lawn increase. As your soil is less compacted, your lawn will take on more water, leading to greener, healthier looking lawns.

Plug Aerators vs. Spike Aerators

Garden Aerator

A spike aerator (or garden fork) doing work on the lawn. source

There are two main categories of aeration tools — plug aerators and spike aerators.

Spike aerators are simple. They’re often manual lawn aerators that require you to poke holes in the soil with a fork-like product.

Plug aerators are still simple, but work differently. Instead of simply poking holes in the soil, they remove a “core sample” of soil while they poke.

In a nutshell: spike aerators can actually contribute to soil compaction as they don’t remove any soil from the ground, while plug aerators both aerate and remove soil, allowing it to be reincorporated over time.

When buying a lawn aerator, choose a plug aerator that takes soil cores of at least 3″ out of your soil. To be more technical, you want one that:

  • Takes 3″ deep plugs
  • Takes 0.5″ wide plugs
  • The space between plugs is about 3″

How to Aerate Your Lawn

If you’re set on aerating your lawn, there are a few tips to help you do it correctly:

Make sure your soil is moist. Aerating a lawn that is dry will make your job a lot harder, as the force required to pull out the plugs is much greater in dry soil. Wait until after a rain or a sprinkler run to aerate.

Allow your soil plugs to dry, then break them down. It’s not necessary to manually break down your soil plugs, but it does help speed up the process. You can run a rake over them to break them down.

Don’t worry about pre-emergent herbicide. A lot of lawn care experts say that you shouldn’t aerate if you’ve already sprayed pre-emergent herbicide. They cite the fact that the “barrier” created by the herbicide is destroyed when core aerating. So far, there’s no evidence to support this claim.

Run over your lawn more than once. Most aeration machines or manual aerators don’t cover much surface area, so it’s a good idea to run over each section more than once for full coverate.

Continue to care for your lawn. Aeration doesn’t solve every thing — you still need to mow, fertilize, water, and care for your lawn.

Lawn Aeration Glossary

Thatch: A layer of decaying plant matter, often dead grass stems and roots. It settles between healthy growing grass and the soil layer, reducing soil compaction and protecting the soil from heat stress. However, if it builds up too much it will actually block essential resources like water, light, and oxygen from reaching the roots.

Compaction: Soil that is too dense. The air pockets within the soil have been minimized, leading to poor water absorption, oxygen flow, and nutrient uptake.

Core Aeration: The process of taking plugs of soil 3-4″ deep out of the lawn, opening it up to receive nutrients, water, and air.

Dethatching: The process of removing the thatch layer from turf. This process is usually done mechanically with a dethatching unit or power rake.

Power Rake: Turf equipment that mechanically removes thatch with rigid wire tines or steel blades, which slice through the turf and lift the thatch debris to the surface for removal.

The Best Lawn Aerators

The Best Lawn Aerator Machine

Agri-Fab makes cheaper aerating products, but they’re mostly spike aerators which are objectively worse than plug aerators, so I don’t recommend any of them.

However, this lawn aerator machine is a class above the rest. It’s by far the best tow aerator on the market, boasting a 48″ wide plug aeration path.

It comes with 32 plug knives, flat-free tires, and weighs only 93lb. It’s a bit pricier than some other options in my recommendations, but if you want an effective aerator machine for large lawns, there really is no better option than the Agri-Fab 45-0299.

Buy on Amazon

The Best Manual Lawn Aerator for Small Spaces

The Yard Butler Lawn Aerator is a great choice…if you have a small space to aerate. It’s a manual step aerator with only two coring sections, though they are 4″ long.

Its best qualities are its  price and its ease of use. If you have a very small space to aerate only occasionally, getting a larger machine is simply overkill. The Yard Butler will do the job just fine.

One caveat: be gentle when aerating, as you can bend the metal if you’re rough with it.

Buy on Amazon

The Best Power Rake / Dethatcher

If you’re having issues with too much thatch on your lawn, but otherwise the soil is fine, you may only need a dethatching tool. While a rake can work, for larger lawns it makes more sense to pick up an electric dethatcher.

The GreenWorks boasts a whole host of features that make it the best choice for a dethatching machine:

  • 14″ path to make quick work of your lawn
  • Fully electric, no carbon emissions whatsoever
  • Tines can be adjusted to 3 different depths
  • Comes with a full set of replacement tines
  • Tines are made of stainless steel for durability
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