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Difference Between Plug and Spike Aerators

By Kate Carpenter

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.

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.

Methods of Lawn Aeration

There are three commonly used methods of aerating a lawn: 1) power raking; 2) tine or spike aerating, and 3) 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 Aeration

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 Aeration

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.

When to Aerate

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.