Proper management practices are necessary to obtain an attractive, healthy lawn. Important cultural practices include mowing, fertilizing, watering, and weed control. Occasionally, it may also be necessary to mechanically remove plugs of soil or aerate the lawn.
Benefits of Aeration
Aeration relieves soil compaction, improves water and nutrient movement in the soil, increases rooting, and prevents thatch accumulation. Aeration improves the growing conditions for the turfgrass plants and results in a healthier, more vigorous lawn.
When to Aerate
In Iowa, September and April are the best times to aerate Kentucky bluegrass and other cool-season lawns. While the overall results are beneficial, core aeration causes some initial damage. Aerating in September or April allows the grass to quickly recover during the favorable growing conditions in early fall and spring.
How Often to Aerate
The frequency of aeration is largely determined by the soil type and the amount of use. Lawns growing in heavy, clay soils and those subject to heavy foot or pet traffic should be aerated twice a year. Once a year should be sufficient for lawns that are established on well-drained soils and experience little traffic.
How to Aerate
Aerate lawns with a core aerator. Core aerators have hollow metal tubes or tines that remove plugs of soil. There are also spike-type devices that simply punch holes (compacting the soil) in the ground. While these devices may help open the surface, core aeration is superior and is the recommended practice. Core aerators are often available at rental agencies. Most professional lawn care companies also provide this service.
Remove soil cores that are one-half to five-eighths of an inch in diameter and 3 inches long. For best results, aerate lawns when the soil is moist. Avoid aeration when soils are dry or excessively wet. The tubes or tines will not be able to penetrate deeply when the soil is dry. The tubes or tines may get plugged with soil when the soil is wet. Lawns that are properly aerated should have 20 to 40 holes per square foot. Since most aeration machines won't remove the proper number of holes with a single pass, several passes are often necessary. After aeration, drag the lawn to break up the soil cores on the soil surface.