Aeration, the process of providing air to plant roots while simultaneously reducing compaction, is one of those lawn chores that’s often forgotten or seldom done. The fact is, without proper aeration, a lawn won’t develop to its maximum potential.

Core aerator

A core aerator is the best method to properly aerate lawns.

Photo Credit: Daniel Overcash

Spike aerator

This spike tool is often believed to be an effective aerator. But it actually causes compaction, which is counterintuitive to the purpose of aeration!

Photo Credit: Daniel Overcash

Often, aeration is done incorrectly by using a heavy, pull-behind tool that spikes holes into the soil. While this tool does a good job of providing a place for fertilizer and seed to get into the soil, it actually increases soil compaction. And compaction reduces the availability of oxygen to reach the lawn’s roots.

The only way to provide proper aeration is to use a core aerator. The tool is usually pulled behind a lawn tractor, though there are some professional walk-behind models. Most core aerators can be rented from the local rental store for half a day. This important piece of lawn equipment removes ½-inch-wide “cores” from the soil that are 2-3 inches deep, every 2-4 inches apart. The holes left where the cores were removed provide a good environment for oxygen and fertilizer to get to the roots, at the same time reducing compaction.

The core aerator leaves the plugs or cores lying on top of the ground. Some people rake these plugs up and remove them from the lawn because they don’t like the unkempt look. But after about the second rain or watering, the plugs will simply melt away.

Aeration can be performed anytime the ground isn’t frozen, but caution should be taken not to do it when the lawn is under stress, like during a drought. (Remember, droughts can occur in seasons other than summer.) I like to aerate one to two days after it rains because the moistened soil makes it easier for the aerator to pull out the cores.

This important lawn-care task should be done once a year. (I like to aerate in fall just before I fertilize and reseed.) In heavily trafficked areas, such as on ball fields, twice yearly aeration can be done, once in spring and again in fall.