For an existing lawn in our area one of the first thing I will recommend to maintain a healthy lawn is to aerate. Clay soils and soils compacted from heavy use may benefit from aeration. Core aerating machines remove small plugs of soil and leave small holes in the ground that allow for better water, air and root penetration. Aerate in the spring or fall, or both, depending on soil compaction or clay content of the soil. In the spring, aerate before applying crabgrass preventers. In the fall it is best to aerate before overseeding. You can rent an aerator from a local nursery or rental agency or hire a professional.
Cores of soil brought to the surface during aeration should be left on the lawn. As they disintegrate, they fall back into the holes and help with decomposition of thatch
