When and How Do You Aerate Your Lawn?

Peak Growing Times & Reasons for Aerating Grass

Lawn aeration taking place

The Spruce / Ana Cadena

The basic idea behind lawn aeration is that, like you, your lawn and the soil under it need to breathe. Aerating a lawn is worth the time and effort because it will help a lawn grow better. But how do you accomplish this? And when should you aerate your grass? Read on to learn how to aerate a lawn yourself and why aerating lawns is beneficial to your landscape.

What Is Lawn Aeration?

Providing much-needed lawn aeration for your grass entails dealing with thatch—which, along with compacted soil, lies at the heart of the matter.

What is Thatch?

Thatch is the loose, organic layer of dead and living material in the lawn: shoots, stems, and roots that develop between the zone of green vegetation and the soil surface. Thatch build-up begins when turf produces organic debris faster than it can be broken down. Not all thatch is bad. A thin layer of thatch in lawns provides insulation against extreme temperatures and fluctuations in soil moisture. More than an inch of thatch, though, can cause problems.

Why Thatch Damages Lawns

Too much thatch can hold excess water, leading to reduced oxygen that reaches turf roots. It can also increase pest problems by harboring disease-causing organisms and insects.

The build-up of lawn thatch makes it difficult for your lawn to breathe. Lawn aeration performed in spring or fall helps control lawn thatch. The process of lawn aeration can be as simple as poking holes in the soil by hand (or by foot with shoe spikes) or with a pitchfork or spading fork here and there (so-called "spiking"), but this would work only for superficial cases. For those in greater need of lawn aeration, this approach will not be sufficient and you will need to perform core aeration. You should also remove as much lawn thatch as you can in the fall by raking deeply rather than just skimming the autumn leaves off the top of the lawn.

Problems With Compacted Soil

Lawn aeration also breaks up compacted soil, allowing water, air, and nutrients to permeate into the root zone. Grassy areas submitted to constant foot traffic (or, worse, car traffic) require lawn aeration more frequently than out-of-the-way areas.

When to Aerate Your Lawn

The best time to aerate your lawn should be when grass is at its peak growing period so it can recover quickly after the process. Here are two rules of thumb:

  • Aeration may be undertaken in the late spring or early summer months for warm-season grasses, such as Bermudagrass.
  • For lawns planted with cool-season grasses (such as Kentucky bluegrass), February (into the first week of March before spring hits) or fall is the best time for core aeration.

Typically, if you don't see any issues with your lawn, you can aerate it every two to three years. However, for high-traffic areas or if your lawn grows in heavy clay soil, annual aerating may be necessary.

Tip

You should not aerate your lawn in the early spring or you will create fertile ground for weeds to germinate. The ideal time to aerate is in the fall, but if it's necessary to do it in the spring, aim for Memorial Day for late spring aeration when weeds have already found a home but haven't yet turned to seed, It's also the best time to amend heavily compacted soil that prevents grass from growing.

How to Aerate Your Lawn

  • Renting an aerator: You can rent a lawn core aerator from a home improvement store or rental center. Since you should not need to aerate your lawn very frequently, it may make better financial sense to rent rather than purchase the aerator.
  • Preparing to aerate: The plug removal process is facilitated by watering the lawn the day before, but don't water to the point of muddying the soil.
  • Using the aerator: This lawn aeration equipment will pull plugs (or cores) of soil out of the ground, letting air in. These plugs should be 2 to 3 inches in depth. Such a plug should be pulled out of the lawn about every 3 inches. Leave the plugs on the grass: they'll break down and add nutrients to the soil.
  • What to do after aerating: Water the lawn every two to three days after aerating. This is also the best time to overseed your lawn but do it fairly quickly after aeration, such as within a couple of days.
  • When to hire pros: If your thatch problem is severe (say about 3/4 of an inch thick or more), rent a vertical mower from a rental center or hire a lawn service to do the job of lawn aeration for you.

Watch Now: 2 Key Lawn Care Tips

Article Sources
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  1. Lawn Care. University of Minnesota Extension