Everyone wants their lawn to be lush and healthy, the envy of the neighborhood. Watering and fertilizer alone will not always produce the lawn you dream of. Depending on the age of the lawn or the soil and growing conditions of the lawn, introducing lawn aeration into your yard care routine can result in a thicker, greener lawn, without too much work.
Aeration is a key strategy to keeping your lawn healthy. The soil beneath a lawn can become compacted or covered with thick thatch, reducing the ability of air, fertilizer or water to seep into the soil and reach the roots. Aeration, usually accomplished with a core aerator, or spike, punctures holes into the lawn by removing small plugs.
What Aerating Does
Aerating a grass lawn is basically opening up the soil to allow the grass roots to breathe by using one of three methods. When grass is grown in heavy clay soil, has deep thatch buildup, or endures a lot of foot traffic, such as on a playing field where the soil becomes compacted, the roots of the grass cannot receive enough vital oxygen or water. Although seldom will a diminished supply of oxygen to grass roots cause the lawn to die, the lawn will become lackluster and sickly looking over time, if oxygen is denied to the roots.
What are the Benefits of Lawn Aeration?
Aeration can improve grass growth and result in a more vigorous, lush lawn. By making the soil less compacted, you can allow more water and nutrients to penetrate the soil and access the grass roots. As a result, roots grow more readily. In addition, the aeration reduces the amount of thatch build-up on the lawn’s surface. An alternate type of aerator, which uses spikes instead of tubes, also helps to open up the soil, though it is less effective than core aerators with tubes.
Nutrients And Absorption
Your lawn will be able to absorb nutrients easier after aeration occurs, and it will be especially helpful in getting these nutrients all the way to the roots.
By creating new air spaces in the lawn, the soil compaction is reduced, which will strengthen the root system.
Thatch is the layer of material between the grass and the soil. If this layer becomes too thick, it will hurt your lawn. Aeration allows microorganisms to increase their movement, which decomposes the thatch layer.
Aeration allows fertilizers and pesticides to infiltrate your lawn and reduces the runoff of such chemicals.
Aerating will make your lawn stronger and more resistant to droughts, heat and wear and tear. The ground will become more cushioned under your feet because of the improved health of your lawn.
Difference Between Plug and Spike Aerators
Methods of Lawn Aeration
There are three commonly used methods of aerating a lawn:
- power raking;
- tine or spike aerating, and
- core or plug aerating.
Each has its benefits and drawbacks, depending on the type of lawn, the use of the lawn and the desired outcome.
An easy way to determine if a lawn needs aeration is to carefully dig out a square foot of lawn that is dug 6 inches down. If the roots are only in the first 2 or 3 inches of the 6 inches, and tangled and balled up, aeration is most definitely needed. But if the roots reach to, or close to, the bottom of the 6 inches and appear to have room to spread, but there is at least 1/2 inch of thatch buildup on top of the soil, hand or power raking may be the better solution.
Spike or tine aeration, as the name implies, is simply putting deep cuts into the lawn soil with spikes. There are power spike aerator machines available for rent; hand-pushed spike aerator rollers; or lawn spike aerator attachments for your shoes. Spike aeration is less expensive to implement than plug aerating, but the benefits of spike aerating a lawn are not as long lasting and should be repeated more frequently.
Unlike plug aeration, spike aerating can be done at anytime during the year, even multiple times in one year.
The visual effects of spike aeration are minimal compared to a lawn that has been plug aerated, and the turf heals much more quickly with spike aeration.
In clay soil, plug aeration is a better choice because spike aeration can actually compress the soil around the cut further, which will add to compaction, defeating the purpose. Spike aeration is better utilized in a sandy soil because it helps with drainage by opening up the soil.
Because of the deep cutting, sometimes up to a foot or more, spike aerating close to underground watering systems or tree and shrub roots must be avoided to prevent any damage.
Plug aerating, also referred to as core aerating, is done with a power machine that removes a 3- to 4-inch plug of grass and soil every 3 or 4 inches throughout the lawn. It is the preferred and most effective method of aerating a lawn, because instead of simply making cuts in the lawn as spike aeration does, it extracts a core or plug from the soil which then allows a direct path for air, water and fertilizer to reach the grass roots. This access to the grass roots will enable a lawn to grow in fuller and healthier.
The visual effect of a lawn that has been plug aerated is not as appealing as a spike-aerated lawn since the plugs that have been extracted are generally left on the surface of the lawn. They will naturally break down and integrate back into the lawn.
Power core aerator machines are available for rent at many home improvement centers and equipment rental shops, or you may choose to hire a professional lawn care service to plug aerate your lawn.
Core Aeration Vs. Spike Aeration
Core aeration machines are usually mechanical and feature hollow tines about 2 to 6 inches apart on a drum. As the aerator moves across a lawn, the tines remove 1/2- to ¾-inch diameter soil plugs that range up to 6 inches long. Lawns should have 20 to 40 plugs per square foot and may require multiple passes with a core aerating machine.
Spike aerators come in a variety of sizes, including large attachments that pull behind riding mowers, manual rolling aerators, shovel-sized aerators and spike-bottomed shoes. All spike aerators punch holes in the soil with solid spikes rather than remove plugs of soil like a core aerator.
Heavy clay soils, lawns that have a large amount of foot and vehicle traffic and lawns with more than a half-inch of thatch (the layer of grass clippings and stems that build up over time) can benefit from core aeration. The process also helps increase the activity of soil microorganisms, which will break down excess thatch.
Core aeration lifts small sections of soil out of the ground and more efficiently provides air access to grass roots than spike aeration. Spikes actually push together the surrounding soil, resulting in greater compaction. Spike aerators, however, come in a variety of styles and can be less expensive than renting a core aerating machine or hiring a professional.
After core aeration, a lawn will appear unkempt for more than a week. Resist the urge to rake up and dispose of soil plugs. They will break down and provide nutrients to the underlying grass. Spike aeration does not result in unsightly soil plugs.
According to Iowa State University Extension specialists, spike aerators that punch holes in the ground can have the opposite effect of their advertised intention and actually result in a more compacted soil. They recommend renting a core aerator from a rental agency or contracting with a professional lawn company to perform core aeration.
When to Aerate
Your lawn isn’t absorbing water and the erosion from runoff water has left dry patches on the lawn where grass has stopped growing and all you have left is dirt. You know you need to aerate your lawn to try to get it to absorb water and nutrients again, but when is the best time to aerate? Well, it all depends on your soil type and your grass type.
Most homeowners need only to plug aerate the lawn once a year, either in the spring, after the last freeze, or fall, before the freeze. If the lawn is not terribly compacted, core aeration can be done every 2 or 3 years for optimum benefit. Spike aeration may be done at any time during the season, and may be applied multiple times during a single season because of the ability of the turf to heal quickly from the cuts and the shorter duration of the benefits of spike aeration.
For heavily compacted lawns, such as one where vehicles drive over it; on which sports events are held; or on which recent construction occurred that had heavy equipment driving over the area, plug aeration is recommended and may be needed two or three times a year. This should be done only in extreme cases, and probably only on the advice of a lawn care professional.
While the ideal timing for aeration varies depending on your climate and your type of grass, aerating early in the growing season allows grass to recover fully from any damage caused by core aeration. Wait to aerate until the ground has thawed, and avoid aerating during periods of extremely hot and dry weather. How often you should aerate depends on how often the lawn is subjected to foot traffic. In most cases, you should aerate one to two times per year.
The type of soil you have dictates how many times you can aerate in a year. A clay soil compacts easily and needs to be aerated twice a year whereas a sandy soil should only be aerated once a year.
When to Aerate
he type of grass you have, or where you live, will dictate when you can aerate your lawn. For example, All About Lawns recommends that you aerate in late spring/early summer for warm-season grasses and in the late summer or early fall for cold-season grasses. Likewise, “Expert Guide to Lawns” also recommends aerating in the fall to avoid over-stressing a lawn.
When not to Aerate
Avoid aerating in the summer. Summers in most areas tend to be hot. And in the Western United States, the air is dry. If you aerate in summer, you risk allowing what little moisture is in the ground out and that could further stress a lawn. Aerating can also remove a protective layer of thatch that is beneficial to your lawn, as it protects it from too much sunlight and evaporation. Another time to avoid aeration when you have a weed problem. Aerating when you have a lot of weeds will spread their seeds throughout your lawn.
How to Aerate Using A Core Areator
To aerate your lawn, make multiple passes over the yard with a core aerator until you have punctured 20 to 40 holes per square foot. Wait until the soil is relatively dry to aerate the yard, as this will help the holes penetrate into the soil more deeply. In addition, damp soil can become plugged in the core aerator’s tubes. For the aeration to be most effective, holes should be 2 to 3 inches deep and, at most, 4 inches apart.
Once you have passed across the lawn several times, use a piece of rough fencing to break the resulting cores of soil into smaller pieces. It may take a few days or a few weeks for the cores to completely break down. Particularly for a thatchy lawn, you can improve the lawn’s overall health by letting the cores work back into the soil. If you’re aerating before planting a new lawn, you can seed immediately following aeration. You don’t need to top-dress the ground after aerating.
Reasons for Not Aerating Lawn
Do not aerate newly sodded or developing, young lawns started from seed, plugs or sprigs. Aeration is disruptive to lawn grass roots and, if plants are tender or not well-established, the puncturing tines may do more harm than good. Withhold any aeration activities until the following year after the lawn has established and filled in as a dense, green carpet with deep roots.
Time of Year
Lawn aeration needs to be conducted at the proper time of year based on the turf grass type. Always aerate at the beginning of the lawn’s active growing season and after it’s been mowed at least two times. Cool-season lawns, such as those with fescue or bluegrass, need to be aerated in the fall or early spring. Do not aerate in summer’s heat or during droughts. Conversely, warm-season lawns — those with zoysia, St. Augustine or Bermuda grasses — need to be aerated in late spring after they green up, after temperatures warm and grow vigorously. Don’t aerate in fall or winter when they’re dormant. Contact your local county cooperative extension office to learn about ideal aeration timing in your region’s climate and considering various lawn grass types.
Condition of Lawn
If your lawn is healthy and there is no more than 1/2 inch of natural thatch build-up, aeration likely isn’t necessary. Some thatch — the decaying clippings that fall on the lawn after mowing — is beneficial for the lawn as it provides nitrogen and shades the soil to help retain soil moisture. Also, if you have earthworms in the soil under your lawn, chances are the soil is naturally porous and in balance, so hold off on aeration.
While lawn aeration helps to alleviate soil compaction and improve drainage of water, do not aerate when the soil is wet or bone-dry. If it’s a rainy weather pattern, hold off aerating until the lawn is not muddy or flooded. The ideal soil condition is moist. Likewise, if you’re in a drought, irrigate the lawn one to two days in advance of aeration. The deep watering softens the soil for coring and the soil moisture benefits the grass roots. Consider postponing aeration if it’s so dry that there are watering restrictions. The aeration doesn’t benefit the turf if it can’t grow with appropriate moisture afterward.