Aeration is a technique used to promote oxygen circulation, increase water and fertilizer uptake, break up thatch, improve root health, prevent water and fertilizer runoff, promote soil organism activity and loosen compacted soil. If this sounds like a magical cure-all for ailing lawns, you may find that it is. Aeration is normally done on an annual basis, but can be performed more or less frequently, depending on your needs.
Aeration is most often completed using a power aerator, which removes cores of soil and deposits them on the surface. The cores will break down naturally over time, and can be broken down more quickly through regular mowing. There is no need to remove the cores, since they will not cause any harm. In fact, the cores will provide nutrients to your lawn if left in place to decompose. Mulch mowing, which is always more beneficial than removing clippings, aids in core break down.
Follow these steps for successful aeration:
Only ever use a core aerator. Spike aerators can contribute to soil compaction.
Plan to aerate in the spring or fall, when the lawn will reap the greatest benefits.
Water your lawn thoroughly the day before. The lawn should be consistently moist, but not soggy or muddy.
Watch for shallow irrigation lines and adjust the aerator depth as needed.
If you have heavy clay soils, consider topdressing with mulch after aerating in order to incorporate organic matter. This will help to break up the clay, making your soil more manageable and better able to absorb water.