Aeration is the process of puncturing small, cylindrical holes or cores in the topsoil using a mechanically driven core aerator. Aerating lawns improves topsoil drainage, alleviates compacted topsoil and effectively removes lawn thatch. Well-aerated lawns have increased microbial activity that aids in the decomposition of thatch and improves movement of water and nutrients to the grass roots, which creates stronger root systems.
When Aeration is Needed
Lawn grass needs to be aerated when excessive thatch buildup or soil compaction exists. Lawns that are heavily trafficked by pedestrians or vehicles are prone to soil compaction and thatch buildup. To check for thatch and soil compaction problems, remove a square-foot section of lawn grass to a 6-inch depth. If the grass roots do not extend more than 2 inches into the topsoil, aeration will be of significant benefit. Additionally, lawns that appear thin or sparse will benefit from core aeration.
Best Time to Aerate
Lawns should be aerated only during periods of rapid grass growth to improve the recuperation time and reduce the risk of weed growth. Cool-season grasses should be aerated from late August to mid-September and warm-season grasses should be aerated between June and July.
The lawn should be moist prior to lawn aeration. The best method is to heavily water the lawn for two or three consecutive days leading up to aeration. By watering the lawn in this manner, the topsoil will be saturated to a deeper level, which allows the cores to be removed more easily and increases the recuperation time of the grass.
How to Aerate
Using a mechanical core aerator, push the aerating rotor at a walking pace over the entire lawn surface. Approach each area of the lawn from at least two different directions to ensure complete coverage. After aerating, leave the cores on the lawn. The core remains will usually work back into the topsoil within two to four weeks.