Aeration is the process of creating openings in the lawn to help air, water and nutrients move into the soil to the grass roots, alleviate soil compaction and help reduce thatch.
An aerator pulls plugs out of the soil coring, spiking or slicing into the soil.
- Core aeration is the most effective method. It uses spoon-shaped or hollow tines to remove columns of soil and deposit them on the surface of the lawn.
- Spiking uses solid tines to create holes in the soil.
- Slicing uses rotating blades to cut narrow slits in the soil.
Spiking and slicing move soil rather than removing it. Although they make less visual impact on the lawn surface, they are not as effective in providing pockets for water, air and nutrients to enter the soil.
For lawns with cool-season grasses such as Kentucky bluegrass and tall fescue, fall is the best time to aerate. With cooler temperatures, you’ll avoid heat stress on the grass and reduce the chance of weed invasion.
Schedule the aeration approximately two weeks prior to the final fertilization for the year and five to six weeks before the first frost to allow the grass time to recover.
For warm-season grasses such as zoysiagrass, centipedegrass, carpetgrass, St. Augustinegrass and bermudagrass the best time to aerate is late spring or in the summer, when the grasses are actively growing.
With either type of grass, warm or cool season, aerate when temperatures are mild.
You can rent aeration equipment or hire a professional. Either way, be sure to mark all sprinkler heads before aeration begins to avoid costly repairs to the in-ground irrigation system.
Before you aerate, test the moisture level of the soil with a trowel. The work will be far easier when the soil is moderately moist. If the soil sticks to the trowel as you remove it, the soil is too wet for aeration.
For the most effective results, make two passes with the aerator: one going north to south, the second east to west. Allow the plugs that have been pulled to remain on the lawn. They will gradually decompose and return their nutrients to the soil.
To speed this process, mow with a low-cutting blade once the plugs are dry. Make two passes, going in opposite directions, to ensure even break-up and spreading of the plugs.
After mowing, water the lawn to help further dissolve the plugs. Your lawn will look better and feel smoother underfoot.
How often should you aerate your lawn? Each lawn varies based on how much foot traffic takes place on the lawn, how much thatch is present, etc. If your lawn looks good, aerating every 3-5 years is sufficient. If there’s a lot of activity it might be worthwhile to consider aerating every two years or annually.