Annual aeration relieves soil compaction, which can be caused by a number of factors, including foot and vehicle traffic. Clippings from mowing the grass can also create a nearly impenetrable layer over time. Or if your lawn was established with sod, its finer texture layered over topsoil’s courser makeup can cause poor drainage.
No matter the cause, compaction can seriously hinder the growth of your lawn. In addition to impeding the flow of water, nutrients, and air, compaction prevents the roots of grass from growing deeper into the soil. A shallow root system can leave your lawn vulnerable to drought and washout. Dead or dying spots and frequent water pooling in your lawn can be indications of compaction.