Aerating is a process that involves pulling small finger-like cores out of the lawn. The cores should ideally be 2.5-3 inches long. The length of the cores is dependent on how hard or compact the lawn is. Aerating is performed to correct compacted soil, improve drainage, improve water and fertilizer penetration and absorption, improve heat and drought tolerance, and improve the effectiveness of weed control. If you have heavily compacted soil, aerating every year, or even twice a year for a couple of years will dramatically improve your situation. If you want to realize the full value of watering or want to maximize the effectiveness of your fertilizer and weed control applications, aeration will certainly improve the response that your lawn will have. Ultimately, aeration is a good idea if you have a lawn that isn’t in the best shape. Alternatively, if you have a great looking lawn and want to keep it that way, make an annual aeration part of your regimen. Golf courses aerate their lawns several times each year.