Why, When and How to Aerate Your Lawn
Grass roots need air, water and nutrients to grow thick, deep and strong. When soil becomes compacted, even slightly, it inhibit the flow of the essentials that support thicker, healthier turf growth. A layer of compacted soil just 1/4 to 1/2 inches thick can make a significant difference in the health and beauty of your lawn.1 Aeration creates holes down into the soil to alleviate compaction so air, water and nutrients can reach grass roots.
Aeration: Why, How and When to Aerate Your Lawn
In order to achieve and maintain a beautiful lawn, you should employ basic lawn care practices such as properly mowing, fertilizing and watering. It is also important to ensure that nutrients can reach the soil beneath your grass. Aeration can be an extremely vital element to a healthy lawn because it allows air and water to penetrate built-up grass or lawn thatch.
Get rid of thatch and make way for a beautiful lawn with this quick guide to aeration. You’ll learn why, how and when to aerate your lawn for the best results.
What is Aeration?
Aeration involves perforating the soil with small holes to allow air, water and nutrients to penetrate the grass roots. This helps the roots grow deeply and produce a stronger, more vigorous lawn.
The main reason for aerating is to alleviate soil compaction. Compacted soils have too many solid particles in a certain volume or space, which prevents proper circulation of air, water and nutrients within the soil. Excess lawn thatch or heavy organic debris buried under the grass surface can also starve the roots from these essential elements.
Should You Be Aerating Your Lawn?
One of the most common questions from homeowners is how to determine if they should be aerating their lawn. Your lawn is probably a good candidate for aeration if it:
- Gets heavy use, such as serving as the neighborhood playground or racetrack. Children and pets running around the yard contribute to soil compaction.
- Was established as part of a newly constructed home. Often, the topsoil of newly constructed lawns is stripped or buried, and the grass established on subsoil has been compacted by construction traffic.
- Dries out easily and has a spongy feel. This might mean your lawn has an excessive thatch problem. Take a shovel and remove a slice of lawn about four inches deep. If the thatch layer is greater than one-half inch, aeration is recommended.
- Was established by sod, and soil layering exists. Soil layering means that soil of finer texture, which comes with imported sod, is layered over the existing coarser soil. This layering disrupts drainage, as water is held in the finer-textured soil. This leads to compacted conditions and poor root development. Aerating breaks up the layering, allowing water to flow through the soil more easily and reach the roots.
When to Aerate Your Lawn
The best time for aeration is during the growing season, when the grass can heal and fill in any open areas after soil plugs are removed. Ideally, aerate the lawn with cool season grass in the early spring or fall and those with warm season grass in the late spring.
Aerating Tools: Plug Aerator vs. Spike Aerator
Two main aerating tools exist — a spike aerator and a plug aerator. With a spike aerator, you simply use the tool to poke holes into the ground with a solid tine, or fork. Plug aerators remove a core or plug of grass and soil from the lawn. For the best results, use an aerating tool or machine that actually removes plugs of soil. Poking holes is less effective and can actually cause additional compaction in the areas around the holes.
Look for an aerating tool or machine that removes soil plugs approximately 2 — 3 inches deep and 0.5 — 0.75 inches in diameter, and about 2 — 3 inches apart. These machines can be rented from lawn and garden stores or home improvement centers. Always follow the directions provided by the store. You may want to consider sharing the rental cost with a neighbor who is interested in aerating the lawn.
How to Aerate Your Yard
If you’re convinced that your lawn is in need of aeration, here are some lawn care tips on how to do it:
- Before you get started, make sure the soil is moist enough. There’s nothing more frustrating than trying to aerate soil that is bone dry. Aerating the day after a rain shower or watering your lawn the day before is advised.
- Most aeration machines cover only a small percentage of soil surface per pass, so make multiple passes over the most compacted areas. Save resources (and your energy) by leaving unaffected areas alone
- The excavated soil plugs should be allowed to dry and then broken up to give your lawn a uniform, clean appearance. Break them up by running them over with a lawn mower or pounding them with the back of a rake. (Your lawn mower blade may need to be sharpened after breaking up the plugs.)
- An aeration myth is that if you apply a pre-emergent herbicide on your lawn in the spring, aerating your lawn will destroy the herbicide “barrier.” This is not true — research shows that aeration will not affect crabgrass control or weed prevention.
- After aerating, it’s important to continue basic lawn care practices such as proper fertilizing, mowing and watering.
Aeration is a beneficial practice toward achieving a beautiful lawn, but most people don’t realize it or understand the process. If your lawn is a candidate, make it an integral part of your lawn care regime. Your lawn will thank you for letting it breathe again.
Why, When and How to Aerate Your Lawn
Simple, regular maintenance tasks go a long way in creating a thicker, healthier lawn. But jobs typically reserved for once a year can play a significant role in supporting smaller steps taken across the months. For many homeowners, aerating lawns to relieve soil compaction and enhance grass growth is a regular annual task. Almost any lawn can benefit from aeration when it’s timed well and done properly.
Why Aerating Helps Lawns
Grass roots need air, water and nutrients to grow thick, deep and strong. When soil becomes compacted, even slightly, it inhibit the flow of the essentials that support thicker, healthier turf growth. A layer of compacted soil just 1/4 to 1/2 inches thick can make a significant difference in the health and beauty of your lawn.1 Aeration creates holes down into the soil to alleviate compaction so air, water and nutrients can reach grass roots.
Deprived of their basic needs by compacted soil, lawn grasses struggle in stressful situations, such as heat and low rainfall, and lose their healthy, rich color. Grasses gradually thin and eventually die out completely, for lack of the oxygen, water and nutrients available just inches away. Even a single aeration session can open the avenue for these essentials to reach their mark and put your lawn back on an upward trend.
Core aerators pull small plugs of soil to the surface.
When Lawns Need Aeration
It may not seem your lawn could get compacted, but it happens easier than you may think. Vehicles or small equipment driven on lawns are more obvious offenders, but even outdoor entertaining or yard play by kids and pets can leave all or part of your lawn compacted. If you live where heavy clay soil is the norm, annual aeration is probably needed to keep your lawn from becoming thin and weak.
Dethatching and aerating are two different tasks, but they often go hand in hand. Thatch is the layer of decomposing organic matter that forms right at the lawn surface, between soil and grass. When thatch gets more than 1/2 inch thick, it works like compaction to prevent the flow of air, water and nutrients grasses need. Aggressive spreading grasses, such as Kentucky bluegrass in northern lawns and Bermudagrass down south, form more thatch than many other grass types. Aeration helps penetrate and reduce thatch buildup or prep it for removal through dethatching.
If your grass often looks stressed and your soil is hard to the touch or rainwater puddles up where it used to be absorbed, you may have compaction problems. Confirm your suspicions with a simple “screwdriver test.” Take a regular screwdriver and stick it into your lawn’s soil by hand. It should slide in fairly easily. If you meet resistance, your soil is compacted, and aeration can help.
When to Aerate Your Lawn
As with most larger lawn projects, such as planting grass seed, it’s best to aerate during or right before the time your grasses reach their peak time for natural growth. Aeration is good for lawns, but it can stress grass if timed improperly. Never aerate dormant lawns.
For cool-season grasses common in northern lawns, early fall or early spring are the best times for aerating. For warm-season grasses common to southern lawns, the best time for aerating is late spring or very early summer. When aeration coincides with active growth, grasses recover quickly and fill in areas where aerator equipment exposes soil.
Aerating is easiest on you (or your equipment operator) and your lawn when your soil is moist from irrigation or rainfall the day before. Overly dry soil can be tough to aerate, so moisture eases the process. Never aerate overly wet lawns; wait a few days instead.
Slicing aerators slice through lawns and leave soil in place.
How to Aerate Your Lawn
Aerating equipment comes in three main types, from small manual versions to larger tractor-like or pull-behind machinery:
- Spike aerators simply poke a hole down into the soil with a solid, spike-like tine. Some homeowners wear spiked aerator “sandals” strapped to their shoes to aerate as they do yard work. While these can help on a small scale, spike machines can make compaction worse by pressing soil together around the holes. 1
- Slicing aerators have rotating blades that cut or slice through grass and thatch and down into soil. Like spike aerators, slicing aerators leave soil in the ground, but they create pathways for air, water and nutrients without causing more compaction.
- Core or plug aerators, typically preferred by lawn professionals, use rows of hollow tines that remove plugs of soil from your lawn and deposit them on top, where they break down. The size of the plugs and the holes they create vary in width and depth, depending on the machine used.
You can hire a lawn service to aerate for you or do it yourself like a pro. Equipment rental companies and lawn and garden stores often rent aerator machines and provide basic operating instructions for the model you choose. Aerating is a lot like mowing as you work back and forth across your lawn. Concentrate on any known problem areas, like pet runs or backyard baseball diamonds. Make several passes in different directions to help ensure optimal coverage and benefits.
What to Do After Aeration
After you finish aerating your lawn, let soil plugs or extra soil dry where they fall. They’ll break down in rain or crumble the next time you mow, adding beneficial soil and organic matter to your lawn surface.
Right after aeration is a perfect time to overseed with premium Pennington Smart Seed and fertilize your lawn or do simple lawn repairs. Seeds and nutrients have direct contact with soil through the openings your aerator created and roots have fresh pathways for the things they need. The combination can help put your lawn on the fast track for quick seed establishment and thicker, lusher growth.
By adding aeration to your annual task list or doing regular compaction tests to check for need, you help ensure your lawn can reach its full potential for thickness, health and beauty. Pennington is committed to providing you with the finest in grass seed and lawn care products to help you achieve your lawn goals.
Pennington and Smart Seed are trademarks of Pennington Seed, Inc.
Sources
- Harper, J. C., “Aeration of Turfgrass Areas,” PennState Center for Turfgrass Science.