There is no ‘perfect time’ to aerate a lawn. In spring the optimal window for aeration is March through April. We do not recommend to aerate in fall as holes left by aerator may not fill in prior to winter freeze and dryness. Aeration done in fall can potentially cause winter kill in lawns.
The deeper the aeration tine or spike the better especially on heavy clay. Aeration can open up spaces in soil for water and nutrients to get closer to the root system of grass plants. Aeration also helps ease the compaction issues from heavy clay soils.
Kentucky bluegrass and bluegrass blends tend to need aeration annually due to their shallow root system and our heavy clay soils. Turf Master native grasses and fescue blends usually do not need aeration though it will not hurt if complete.
Primary Benefits of Lawn Aeration are, Oxygen, Water and Nutrients, all of which are life giving substances necessary for growth. Aeration will allow oxygen, water and nutrients easy access and interaction with the roots. It is important to follow up with fertilizer and if needed overseed the lawn after aeration.