Core aeration is the process of mechanically removing plugs of thatch and soil from the lawn and should be done every 3 years. Aeration opens the soil, helps reduce compaction, improves water infiltration, improves rooting, reduces thatch and acts in many other ways to improve the lawn and reduce stress. Lawn aeration restores the vital “nooks and crannies” to the soil. To maintain a healthy lawn through periods of stress, the soil needs water, air and nutrients in the top 6 to 10 inches. Soils that are hard and compacted like our clay, have no “nooks and crannies” to hold the water, air or nutrients. Without these crucial components, root growth is impeded, which prevents the grass from developing the deep root system that is essential to survive in hot and dry or harsh and cold periods. Core aeration can be used to minimize thatch accumulation, to modify its physical characteristics, and to reduce soil compaction. Soil plugs are deposited on the turf surface (see left). These plugs then break down and redistribute soil throughout the thatch layer. The soil from the plugs helps to modify the physical structure of the thatch, making it a better growing medium.