Core aeration pulls small plugs of soil so air, water, and nutrients can reach the roots. That loosens compacted soil and helps with a thick thatch layer.

Aerate while the grass is growing so it can recover. Cool season grasses such as fescue are usually aerated in early fall, and warm season grasses such as bermuda and zoysia are usually aerated in late spring. Skip a dormant lawn.

Once a year is enough for many home lawns. Clay soil, heavy foot traffic, or thick thatch may call for a second visit.

Yes. The holes give fertilizer a path into the soil, and you should water afterward if the product label says to. Seed can go down in the same window, while the holes are still open.

Do not cover the lawn with a thick layer of topsoil, and leave the plugs so they break down. Hold off on heavy use for a few days. Mow when the grass needs it.