Skip to main content

How to find the best time to plug aerate your lawn

Grass does not grow well in compacted soil, as packed earth resists roots, water, and air penetration. It makes a poor environment for beneficial microbes to grow and lacks organic matter, which is a hallmark of fertility. Without intervention, a compacted soil zone can spread as weak grass dies off, roots decay, microbes go dormant or die, and soil particles settle closer to one another. Aerating the lawn helps to reverse these effects and prevent soil from becoming compacted.

Ride-on core aerator working on a lawn
Image used with permission by copyright holder

What is aeration?

Aeration is, in essence, perforating the soil surface to allow air, water, nutrients, and roots to penetrate deeper. Various tools and implements can be used to do the job, from spiked shoe attachments that you can strap on to walk around the yard to vertical mowers with blades that cut into the soil surface. The most effective aerators are plug aerators.

Plug aerators are heavy rollers with long, hollow tines spaced 6 or 8 inches apart. Some are self-propelled, walk-behind machines. Others are built to tow behind a lawn tractor. As the aerator rolls across the grass, the tines sink down and pull out soil plugs approximately a half-inch in diameter and 1 to 2 inches deep. The plugs are left on the lawn surface to dissolve in the rain.

Aerating can turn a struggling lawn around. Since grass roots are cut in the process, it is a stressor in the short term. If the soil isn’t compacted, aerating isn’t necessary. However, if the lawn needs to be aerated, be sure to do it at the right time of year to minimize plant stress and maximize the benefits.

A lawn of tall fescue grass
Image used with permission by copyright holder

Causes of soil compaction

Heavy clay soil

Heavy clay soil has a natural tendency to become compacted over time, unless it’s protected from the hot sun by dense vegetative growth and kept moist to allow root penetration. A dense, well-established lawn on clay soil may thrive without symptoms of compaction, but certain stressors like drought, heat, or improper mowing height and frequency may cause it to decline.

High levels of traffic

High traffic situations, such as dog runs along fences or the kids’ direct path to the treehouse, don’t just kill the grass. They also cause soil compaction that prevents new grass from growing.

Poor drainage

Low lying areas and uneven surfaces both drain poorly. Water lying on the surface for an extended time kills the vegetation and microbes living in the soil, causing the soil structure to collapse. Over time, this kind of ponding may become worse because of the added soil compaction.

a recently aerated lawn
Image used with permission by copyright holder

What will aeration do for the lawn

Grass that grows in compact soil exhibits one or more unsightly, unhealthy stress symptoms. By improving the soil structure, aerating addresses these maladies. These issues can all be reduced or eliminated with aeration:

A well-aerated lawn grows deeper roots, gains access to a more substantial supply of water and nutrients, and generally becomes more resistant to pests, diseases, and drought. The grass takes on a stronger, healthier, more consistent appearance.

Bright green St. Augustine grass
Image used with permission by copyright holder

How to tell if the lawn needs aeration

Only compacted soil needs to be aerated, but some people aerate annually as preventative maintenance. A simple screwdriver test will indicate whether or not the lawn soil is compacted. You’ll need a Phillips-head screwdriver, with a 6- to 8-inch blade.

In several areas of the yard, especially in places where the grass grows sparsely or slowly, push the screwdriver into the soil as deeply as possible. If it sinks all the way to the handle with little effort, the soil isn’t compacted. If you feel substantial resistance, or if you can’t insert the screwdriver fully, aerating will help.

plug aerator closeup
Image used with permission by copyright holder

When to aerate your lawn

The best time to plug aerate a lawn is at the beginning of its normal rapid growth phase. Warm-season grasses,  like bermuda grass and zoysia grass, should be aerated in late spring or early summer, once they’re fully green. For cool-season grasses, late summer or early fall is best. If you plan to overseed fescue in the fall, aerate first.

When the season is right, wait for a spell of soaking rain. The aerator’s tines will penetrate moist soil more deeply than dry soil, but it shouldn’t be too wet. Wait four or five days after the rain has passed before aerating.

Grass grows best when it develops a deep root system that can access abundant moisture and nutrients. Dense soil resists deep root development, but aerated soil fosters it. If your lawn has been struggling, aeration could be the cure.

Editors' Recommendations

Mark Wolfe
Former Digital Trends Contributor
Mark Wolfe is a freelance writer who specializes in garden, landscaping, and home improvement. After two decades in the…
Why mulching might be the best option for your old Christmas tree
Turn your Christmas tree into eco-friendly mulch
Person carrying old Christmas tree

The gifts have been exchanged, the parties have ended, and you're ushering your relatives out the door so you can enjoy the last of the holiday season in peace. There's just one lingering loose end to tie up: What in the world are you going to do with that huge, old Christmas tree?

If you have an artificial tree that’s still in good shape, the answer is simple — just pack it back into the box and put it into the attic or garage for another year. What about a natural tree, though? With environmental sustainability an ever-growing consideration for consumers, it’s no longer as simple as tossing the tree into the next available garbage truck.

Read more
A guide to winter lawn fertilizer for keeping your turf healthy this season
Tips for picking and applying winter lawn fertilizer
Person pushing a lawn fertilizer spreader

Besides mowing and watering, part of keeping a lush lawn is fertilizing it properly in the fall. If you've ever shopped for grass fertilizers, you may have heard of winterizing fertilizer. Basically, this type of lawn food, typically a nitrogen-heavy version, prepares grass with an energy reserve for winter. For an explanation of how winter lawn fertilizer works and how you should apply it, read ahead.

Why would you fertilize your lawn during the winter?
Fertilizing way ahead of the growing season will help your grass grow healthy when the temperature warms up. You might see companies refer to such seasonal fertilizers as winterizing fertilizers. This name is somewhat misleading since you want to apply the fertilizer during late fall when grass growth slows down. They're all about preparing your grass for winter.

Read more
Can you leave beets in the ground over winter? Here’s your guide on how to store beets for the winter
Find out if you should overwinter your beets
Beets laying on a table

As winter approaches, there’s sometimes a rush to get all your vegetables harvested and stored in time. Produce left out in the garden during winter can rot or develop frost damage quickly, but is that true of all vegetables? Some gardeners choose to leave beets, as well as other vegetables, in the garden through winter. Is this a wise decision? What are the potential benefits and drawbacks of overwintering your beets like this? Here's everything you need to know about how to store beets for the winter.

Can you leave beets in the ground over winter?
Yes, beets can stay underground through winter. Several other root vegetable plants, including parsnips, turnips, and carrots, can also be left underground. In most cases, they will last just fine without significant damage. However, there's still a slight risk of rot or frost damage. Leaving beets underground during winter, also known as overwintering, is better suited for vegetables planted in the fall.

Read more