One of the most time-consuming and, at times, frustrating responsibilities of homeownership is maintaining a healthy lawn.
Besides watering, feeding, and mowing on a high setting, aerating is one of the best things you can do for your lawn. Aeration is the process of puncturing small holes in the ground to break up the soil and give water, oxygen, and nutrients easier access to the grass roots.
But the question is: how often should you aerate your lawn?
Aeration should be done once a year for healthy lawns and twice a year for lawns with compacted soil and thatch buildup. The best time of year is just before the high-growth season, which, for cool-season grass, is the beginning Spring and Fall and, for warm-season grass, is late Spring.
That’s the short answer, but there’s more to know about aeration before you get started.
In this quick guide, you’ll learn the basics of lawn aeration, including the factors that impact frequency, why overseeding often accompanies aeration, and the simple steps to do it yourself.
Use the links below to navigate:
- Factors That Impact Aeration Frequency
- How to Know if Your Soil Is Compacted
- How to Know if Your Lawn Has Too Much Thatch
- The Best Time of Year to Aerate Your Lawn
- Aerating and Overseeding
- Equipment You Need to Aerate Your Lawn
- How to Aerate Your Lawn
Factors That Impact Aeration Frequency
Compacted soil, as its name suggests, occurs when soil particles are pressed or compacted firmly together.
Compacted soil occurs most often in heavily trafficked areas, like sports fields, playgrounds, new construction lawns. It also occurs when the soil contains a high amount of dense materials like clay, which is common in states like Texas and Louisiana.
The high density of compacted soil limits space for water, oxygen, and nutrients to reach the places they are needed, like grass roots. Compacted soil also makes it difficult for grass roots to expand since breaking through dense soil takes significantly more energy. Due to the unhealthy conditions created by compacted soil, more frequent aeration is necessary.
Over time, dead grass clippings, shoots, and stems accumulate on the top layer of the lawn, creating a barrier between the grass blades and soil. This barrier is called thatch. A small amount of thatch is beneficial because it adds nutrients back into the soil, but when it builds up faster than it decomposes, it creates a barrier and blocks water and air from passing through.
Compacted soil and excessive thatch result in malnourished and unhealthy lawns. Aerating solves for both of these issues by breaking through thatch and plugging holes in compacted soil opening up pathways that were previously closed off. Whenever excessive thatch and compacted soil are present, more frequent aeration is necessary.
How to Know if Your Soil Is Compacted
As long as you know what to look for, it’s relatively easy to detect when your soil is compacted. Here are the tell-tale signs:
- Bare spots and areas with patchy, unhealthy looking grass. When water and oxygen can’t reach the roots, grass can’t grow.
- Rock hard soil that you can barely penetrate with a pitchfork.
- Water running down from high areas is a sign that your lawn is not absorbing water.
- The Soil has a reddish tint. This is a sign of soil with high clay content, which tends to become compacted.
- Plants with stunted growth and trees with shallow roots.
- If your lawn doubles as a playground for kids or pets, there’s a good chance the soil is compacted.
If your grass is thick, green, and healthy, and none of these signs are present, the soil is likely in good shape. If this is the case, stick to an annual aeration schedule until conditions change.
How to Know if Your Lawn Has Too Much Thatch
The best way to determine if your lawn has too much thatch is to walk on it and feel it with your bare feet. Lawns with too much thatch feel spongy and bouncy. Healthy lawns are soft but firm.
Feel the grass with your hand and fingers too. Your finger shouldn’t be able to press more than a half-inch into the thatch. If you’re still not sure, dig up a small chunk of turf and look at it from the side. If the layer of thatch is thicker than a half-inch, your lawn has too much.
If thatch is accompanied by compacted soil, the best solution is aeration. If thatch is the sole problem, you can “dethatch” your lawn by raking it manually or renting a power dethatcher from a home improvement store like Home Depot.
The Best Time of Year to Aerate Your Lawn
The best time of year to aerate your lawn is just before the high growth season, which varies by grass type. The best time of year to aerate cool-season grass, like Kentucky bluegrass and creeping red fescue, is at the beginning of the Spring and Fall. The best time to aerate warm-season grass, like St. Augustine grass and zoysia grass, is late Spring.
If you’re not sure what type of grass you have, this helpful resource on Scotts.com will help.
The growing season is the ideal time of year to aerate because roots will take advantage of their newly found access to water and nutrients, helping the lawn recover quickly as they grow.
Aerating and Overseeding
Aerating is often accompanied by overseeding, which is the process of planting grass seeds on the existing lawn without tearing up the grass or soil. The holes that aerating opens up are the perfect home for new grass seeds from overseeding to germinate. The combination of both processes at the right time of year, just before the growing season, will result in a thick and healthy lawn and leave no space for weeds to sneak in.
Equipment You Need to Aerate Your Lawn
Before you can aerate your lawn, you need to buy or rent an aerator. Aerators are specialized equipment, and there are three main types. Here’s what you need to know:
Spike Aerators break up thatch and compacted soil by piercing holes in the ground. There are several types of spike aerators, including tools that look like pitchforks, spike rollers, and even spiked shoes that you strap to your feet and aerate as you walk on the lawn. Some people love spike aerators because they are simple and usually the cheapest type of aerating equipment. Others claim that they are the least effective and can make compaction worse by pressing the soil between each hole closer together. If you decide to go with this option, make sure you read reviews and understand how to use it properly.
Slicing aerators are the next best option. They use rotating blades to slice through thatch and soil to loosen it up and create space for water and air to flow. Like spike aerators, there are inexpensive options to choose from, but there is debate over their effectiveness.
Core aerators, also referred to as plug aerators, are the most popular type of aeration equipment, and for a good reason, they are the most effective. Instead of pushing a spike or blade into the ground, which can make compacted soil worse, core aerators use hollow tines to pull small plugs of soil out of the ground creating a channel for water, air, and nutrients to penetrate. The plugs of soil are discarded on top of the lawn, where they decompose and add nutrients back in. Core aerators come in many different forms, including ones that you tow behind your mower, manual tools, and gas-powered commercial size machines that you can rent from Home Depot.
How to Aerate Your Lawn
Aerating your lawn is simple and easy. Regardless of which type of aerator you choose, these are the steps you need to take.
- Step 1: Make sure the soil is moist — water a few hours ahead of time or plan to do it on a rainy day.
- Step 2: Mark sprinkler heads, shallow utility lines, and plumbing before you get started, so you don’t accidentally puncture any of those.
- Step 3: Carefully go over each section of your lawn, which your aerator like you would with a mower. If you’re the soil is significantly compacted, or you haven’t aerated in a couple of years, go over it twice. On the second pass, go in a different direction to create new holes.
Once you are finished, water generously. Some professionals recommend applying fertilizer to assist in recovery, but it’s not completely necessary.
Do You Have Aerating Tips To Share?
Now that you know how often you should aerate your lawn, it’s time to get to work!
What has been your experience with aeration? Does it improve your lawn? How often do you do it? What type of aerator have you used? Let us know in the comments below!
The information in this post was based on consulting with local landscapers and my own research. These are the sources I’d like to thank:
- Local landscapers: A to Z Landscaping, A. David Lawncare, Folan’s Landscaping
- Resources: TruGreen, Scotts, Home Depot Garden Club
- Photos: Jonathan Green, Garden Myths, Cornell Turfgrass Program
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