Left alone, grass would grow tall and billowy, sinking roots deeply. These deep roots would break up soil and form an anchor enabling turf to withstand summer heat and drought with ease. The typical homeowner, however, doesn’t leave grass alone. Instead, we cut and edge and blow, grooming a manicured swath of sparkling green. The activities associated with maintaining a lush lawn combine to compress soil, which suppresses root growth and hinders roots from penetrating into soil.

If a lawn grows for years without aeration, the soil beneath will eventually harden, shrugging off fertilizer, rainfall, and supplemental irrigation. As soil becomes tighter, grass grows less, thinning and eventually dying.