Best Time to Aerate Your Lawn

Why is it that one lawn appears green and lush most of the year and another lawn, right next door, is lackluster, patchy and sparse?

The answer – the healthy lawn has probably been aerated.

But what is lawn aeration, why is it so vital to lawn care and how do you aerate your lawn?

In this article, we address what aeration is, the best time to aerate and overseed the lawn, how to do it and why it is necessary.

Related post: Seasonal Lawn Care Guide and Tips

What Are The Basic Lawn Care Practices?

To maintain or establish an attractive expanse of lawn is easy if you follow the general practices like:

• regular mowing the grass
• when and if you fertilize your lawn
• how often you water your lawn
• aerating your lawn

But what part does aeration play in achieving a well manicured lawn?

Just like we need to breathe in order to live, so to do lawns. Aerating your lawn is the process whereby small holes get punctured into the soil, below the grass. This allows the lawn to “breathe”.

The “breathability” of a lawn allows vital elements like air and water to penetrate the soil, just below the surface.

Oxygen and water are crucial for the grass roots to penetrate deeper and thus take up more nutrients and water.

Why is lawn aeration necessary?

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Over time the soil under the grass becomes compacted. This could be due to a few factors.It may be that a lawn that gets walked over or played on often. It could also be that a build-up of lawn thatch is inhibiting the optimal growth of the grass.

Compacted soil – The soil particles increase in volume as they harden and become solid. The build-up of thatch also becomes too thick. The roots then get starved of air and moisture, resulting in poor quality lawn with weak stems.

Lawn thatch – This thatch is necessary for the lawn’s health as it creates a thin layer of mulch and assists the water in soaking deeper into the soil, as well as keeping the soil moist for longer.

Fertilizer will also break down faster when the lawn thatch is aerated and loosened thus supplying the soil with vital nutrients like nitrogen, potassium, and phosphorous.

But if the lawn thatch gets too fibrous and thicker than ½ inch it becomes detrimental to the root and stem development of the grass. This is when scarification will be applied.

A lawn that is compacted eventually becomes undernourished.

The undernourished lawn is susceptible to insect infestations, from ants to spiders to crickets. The compacted lawn will also pick up disease more readily.

Lawn fungal infections like Fusarium, Fairy Rings, Corticium, and Ophiobolus may appear.

Lawn aeration solves these problems by allowing the water, fertilizer, and air to penetrate the surface layer of the grass. The roots can absorb what it needs for strong healthy blades of grass to form and for optimal photosynthesis to take place.

How often should I aerate my lawn?

Core aeration is only necessary once every 3-5 years, again this will depend on how much traffic the lawn endures as well as the type of soil the lawn is established on.

Obviously, a sandy soil won’t need core aeration and clay soil will need regular aeration. 

The perfect soil is a loamy, well-drained type but it is not always affordable or practical for a home gardener to establish a lawn with perfect soil.

Even if you start a lawn off by adding a suitable layer of topsoil, eventually the topsoil will mix into the original and you’ll have compaction.

When is the best time to aerate and overseed lawn?

Core aeration is best carried out in spring or fall when temperatures are cooler and the recovery time will not be inhibited by extreme heat or cold.

If you are in the North and have cool-season grasses, like Kentucky Bluegrass, then fall is ideal. This is especially true if you are going to be overseeding.

Related post: How Long Does It Take For Grass Seed To Grow After Overseeding?

If you are in the South with warm-season grasses, like Bermuda, then spring is better. Early summer is even more ideal.

If you stay in a region that is sub-tropical spring or fall is good.

Related post: When to Stop Watering Your Lawn in the Fall

Scarification should be carried out monthly during the growing season, in conjunction with mowing. This reduces the build-up of thatch, which in turn reduces or eliminates the appearance of certain creeping weeds like clover.

The main objective when scarifying is to prevent the thatch from forming a solid seal or “skin” over the soil surface.  It is best carried out at the end of the dry season, or before artificial watering is carried out.

Large and small tools and equipment are available for this job.

What tools and machinery are needed for lawn aeration?

Today there is a large selection of tools and machinery available for aerating.

• Spike aerators
• Slice aerators
• Plug/core aerators

There is even a strap-on option for people who want to attach aerators to their boots and just walk around spiking the lawn with each step!

Then there is the old-fashioned hand roller aerator, with spikes.

If you need to scarify, a hand roller rake, also known as a scarifying roller rake, will be sufficient.

For dethatching over small areas, hollow tine forks are available, as are hollow tine rollers. For larger home gardens electric dethatcher/aerators are available.

For core aeration over large areas, it would be better to hire a core aerator for the day or hire a garden service that will come in with their own machine.

How To Aerate Your Lawn? Different Forms Of Aeration

There are two forms of aeration. One dealing with the immediate surface and the other with the soil below.

The aeration done on the surface to reduce fiber or build-up of organic debris, also known as lawn thatch, is called scarification or dethatching.

This deals with soil compaction and is done less frequently than scarifying. Core aeration deals with the soil below.​

Removing excess thatch

Before aeration, the excess thatch must be dealt with. Spring or fall is a good time to do this. If the thatch is ½ inch or more then it is too much.

You can solve this by giving a good deep rake. This loosens the thatch and the excess can be raked up and added to the compost heap.

Though dethatching is not the same as aerating, you can have a machine do the work instead of by hand.

how to easily scarify your lawn

If you have a tiny patch of lawn, aeration can be as simple as taking a garden fork and spiking the lawn in rows.

Simple forking or spiking promotes root development. But for larger lawns, this method is time-consuming and won’t improve serious compaction much.

If using a solid tine fork to spike the soil, the best way is to spike at 3 – 4 inch intervals and to a depth of around 4 – 6 inches.

Scarification is the best aeration method when there is much fiber in the lawn (thatch).

Scarification is suitable to perform just before fertilizing, and as such can be done once a year in the early summer before the rains come.

After the thatch has been dealt with fertilizing can take place.

Core Aeration

Core aeration is the method used to penetrate the soil with the appropriate tools or machinery.

The ideal plug size should be ½ – ¾ inches wide and 2 – 3 inches in depth.

It is a good idea to water the lawn the day before. This loosens the soil slightly, making the process more efficient.

It also means less damage to the lawn, as the plugs get pulled out. The pulled-out plugs can either be left on the lawn and then raked out as a type of lawn dressing.

But only if the soil is friable and breaks down easily. If the soil is clay and hard then it is best to remove the pulled plugs completely. The best way to aerate would be to hire or buy a proper lawn aerator and perform core aeration.

Another option is to hire a garden service to come in and do the job for you. For small areas, hollow tine forks will do the job nicely.

How Do I Aerate By Hand?

Aerating by hand, although slightly more time-consuming and requiring a bit more “elbow grease” is actually really easy.

There are hand rollers with spikes If the area to be aerated is small, even using a fork will suffice. Forks with hollow tines are available as well.

To aerate by hand (without using a roller) you will need a fork. Insert fork at 3 to 4-inch intervals and make each insertion between 4 to 6 inches deep. It is as easy as that!

What about aftercare once aeration is complete?

The only aftercare needed when aeration is complete would be to water regularly. This will promote new root growth in the hollows left by plugging. If you have also sowed grass seed then watering is even more crucial.

• After aeration is a perfect time to overseed and/or fertilize.
• Fertilizing can be done after scarification in spring, fall or early summer, as mentioned above.

If core aeration was done, the removed plugs will need to be taken care of. This means you will need to break hard plugs either by mowing or raking.

The blades should take care of any clods remaining.

This will also aid any new seed as it germinates. ​​Applying a weed-free lawn dressing after aeration will ensure the plugs get filled with a lovely soft, friable medium.

Lawn dressing promotes new growth as well as filling in gaps and uneven surfaces on the lawn.​

What are some FAQ’s regarding lawn aeration?

What will it cost me to aerate my lawn?

The national average comes to roughly $120 to $130 for an average size yard.​ Anything between $70 to $200 is a typical range.

At the low end of the spectrum you could pay as little as $45 to $50.And at the top end you can pay as much as $350.

These prices range depending on whether you hire in a service to do the job or rent a lawn aerator for the day. Both manual and motorized machines are available bringing the rental fees in at anywhere between $60 to $250 per day.

Sometimes fertilizing at the same time will save you money in the long run, as you wont need to pay labor or machine costs for another day.

If you want to own your own aeration machine, we reccomend the Greenworks

How soon after aeration should I seed?

The best time to seed is at the same time that you aerate. First, aerate and then on the same day sow the seed.

Overseeding is the process of adding seed to your existing lawn. The benefits of this are two-fold.

By using a different type of seed to what you already have keeps lawns greener longer, makes the lawns more drought-resistant, and evens out bare spots.

Grass becomes thicker choking out weeds. And when sown on the same day the new seeds get the benefits of the water and fertilizer and grow fast, again giving weeds less chance to take over.

Is it better to fertilize before or after aeration?

As for seeding, fertilizing on the same day as aeration is the best option. It saves time, labor and costs.

Also after aeration, it is advised to water so when you add fertilizer at the same time the roots that will soon develop from the aeration process are given a boost with the added fertilizer. This means your lawn will be green, thick, and weed-free, especially if overseeding at the same time.

How do I overseed without aeration?

This can be done by first mowing the lawn close to the surface. Then, using a metal rake, loosen the thatch and rake up cut grass and dead leaves.

Related post: How Long Does It Take for the Various Types of Grass to Grow?

You can spread the seed by hand or use a drop spreader (like the one below).

The amount used will also depend on how thick your current lawn is.

You can rake the seed (and starter fertilizer 1:1:1) in to make sure there is contact with the soil surface.

Water lightly to help the seeds to settle, without dislodging. Water lightly again an hour or so later.

After that water twice a day until seeds has sprouted and rooted.

Regular watering can continue using a garden hose but use a fine spray nozzle (or oscillating sprinkler) until seedlings have established themselves.

After 6 weeks fertilize again using 3:2:1 nitrogen-based fertilizer.

Takeaway

Besides regular mowing, fertilizing, and watering, aeration carried out when needed will give your lawn the edge.

And it will be your neighbors, not you, saying the grass is always greener on the other side (of their fence).