Aerate cool-season grasses (Kentucky bluegrass, fescue, perennial ryegrass — the grass most QC lawns have) in early fall (mid-September through October) or early spring (April through May). Fall is the better window — the grass is actively growing, the soil has moisture from cooler weather, and the lawn has time to recover and fill in before winter dormancy.

Avoid aerating in mid-summer heat or in dry conditions — the cores will not pull cleanly from rock-hard soil and the lawn is already stressed. Spring aeration is acceptable but pair it with overseeding if you also want to thicken the lawn (the Ecolawn 250 self-propelled compost spreader and overseeder is a great pair-rental).

Soil moisture matters more than calendar date. Aerate 24-48 hours after rainfall or after watering thoroughly. The cores should pull intact, 2-3 inches deep. The Commercial Z Turf Ride-On Aerator is fast enough that most residential lawns and athletic fields take less than an hour. Call (563) 271-4732 to reserve — spring aeration season fills up fast.