Aeration is the naturally occurring process of air exchange between the soil and its surrounding atmosphere. Aeration is the process of mechanically removing small plugs of thatch and soil from the lawn to improve natural soil aeration. This helps the roots grow deeply and produce a stronger, more vigorous lawn.
The main reason for aerating is to alleviate soil compaction. Compacted soils have too many solid particles in a particular space, which prevents proper circulation of air, water and nutrients within the soil. Excess lawn thatch or heavy organic debris buried under the grass surface can also starve the roots from these essential elements.