Mechanical aeration alleviates soil compaction in established turf, encourages root growth by increasing oxygen to roots, and allows seed, lime, and fertilizer to enter into the soil.
- Compaction occurs primarily in the soil surface. A compacted layer as thin as one-fourth to one-half an inch can greatly impede water infiltration and gas exchange between soil and atmosphere.
- Aerating machines should remove plugs of soil from the turf, creating a system of large pores by which moisture and plant nutrients can be taken into the soil. They are referred to as core aerators. Core aerators pull plugs about ½- to ¾-inch in diameter, 2 to 4 inches deep, and about 2 to 6 inches apart. Equipment having solid tines or spikes should not be mistaken for aerating equipment. These types of machines actually increase soil compaction by compressing the soil into a denser mass.
- Fall is the best time to aerate cool-season lawns, and June through July is the recommended time to aerate warm-season lawns. Never aerate when a lawn is dormant. A general rule is to aerate only when desirable grasses are growing vigorously.
- Soil should be moist, but not wet, before aerating. Irrigate the lawn prior to aerating if the soil is dry.
- Aeration can be done before overseeding. This procedure makes holes for the seed to fall into, therefore increasing seed-to-soil contact.
- Core aeration should be performed every one to two years on lawns that receive heavy foot traffic. Otherwise, aerating every two to four years on home lawns is sufficient.
- Soil plugs can be left on the surface of the lawn. They will decompose in a couple of weeks.