When you aerate a lawn, you make holes in the lawn (and the soil beneath) by either pushing short spikes into turf and soil or by extracting a small plug of soil, also known as coring.
Aerating produces several results:
- Oxygen can reach turf roots and soil.
- Fertilizers and nutrients can enter soil and come into contact with roots.
- Water soaks into soil more efficiently, easily reaching grass root zones.
- Thatch is physically disrupted and broken up.
- Compacted soil is loosened.
Why Aeration Is Needed
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 you don’t aerate your lawn every few years the soil beneath will eventually harden, shrugging off fertilizer, rainfall, and supplemental irrigation. As soil becomes tighter, grass grows less, thinning and eventually dying.
Thatch Compounds the Problem
Grass plants naturally spread over soil, and occasionally, parts of individual turf plants die and begin to decompose. The thin layer of dead and decomposing bits of grass that lies between actively growing shoots and soil is called thatch. A moderate thatch layer is actually beneficial, insulating soil from sunlight and reducing water evaporation.
If thatch builds up to more than one-half inch, it begins to interfere with water, fertilizer and oxygen absorption by soil and grassroots. When a thick thatch layer is present, turf actually roots into the thatch, which offers no nutritional support—and further weakens the lawn.
When thatch exceeds one-half inch, the most reliable way to break it up is to aerate, followed by raking with a thatch rake. Regular lawn aeration prevents thatch build-up, as does proper fertilization and watering.
Benefits of Aeration
The single greatest result when you aerate your lawn is that compacted soil becomes loose, which unleashes a cascade of events that foster healthy grass:
- Turf roots can penetrate and spread easily in loose soil, forming the network needed for grass to withstand summer heat and drought.
- Openings punched into soil and thatch allow oxygen to permeate the grass root zone environs. Oxygen helps prevent the spread of fungal diseases and enhances the growth of microorganisms that digest lawn thatch.
- An aerated lawn also permits fertilizer and water to reach plant roots, which favors healthy growth.
- Thick, healthy turf withstands pest attacks, elbows out weeds, and gives your home eye-catching curb appeal.