Core aeration leaves plugs of soil on your lawn that break down and help discourage thatch. Adele Wilcoxen .
Core aeration leaves plugs of soil on your lawn that break down and help discourage thatch. Adele Wilcoxen .

KC Gardens

Answering your gardening questions from asters to zoysia

KC Gardens

Core aeration gives your lawn’s roots a boost

By Dennis Patton

Special to The Star

September 16, 2017 08:00 AM

Who doesn’t like a beautiful green lawn? We aim for a lush look, sometimes at the expense of the grass roots. But now is the time to take care of them, because a healthy root system is a must for an attractive lawn.

Oxygen in the soil is vital for strong roots. Kansas City’s heavy clay and compacted soils often inhibit root growth. Core aeration improves rooting and problem soils without destroying the turf. Now is the time to perform this important task.

Core aeration provides several benefits. It helps break up compaction of the soil caused by construction or traffic such as walking or kids playing. This miracle process also reduces the buildup of thatch, improves water and nutrient infiltration and adds oxygen while releasing carbon dioxide. All of these things encourage roots to push deeper into the soil.

The machines are slightly larger than a lawn mower and can be rented from many nurseries, hardware stores or rental agencies for a nominal fee. Commercial grounds maintenance firms also provide this service. Running a machine is comparable to using a rototiller.

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Aeration on bluegrass and tall fescue lawns is best done September through October. Spring is also acceptable. For heavily compacted lawns, fall and spring aeration may be required. Be sure the soil is moist to get the maximum benefit. Dry soil will inhibit the hollow tines from penetrating the soil.

Core aeration provides maximum benefit if it is done yearly. The holes made in the soil should be about 3 inches apart and 3 inches deep. The tines make holes about  3/4 inch in diameter. Several passes in different directions will be necessary to achieve the correct spacing.

Aeration will result in plugs of soil scattered around the lawn. Just leave them in place to naturally break down. As the plugs decompose, the soil naturally settles, helping to break down the thatch and renewing the lawn.

Aeration is an important part of a lawn care program. There are no real physical signs to alert you to when the lawn needs aerating, but research has proved its value. So take advantage of this fall season to help improve your lawn and its often overlooked roots.

Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Got a question for him or other university extension experts? Email them to or visit