Aeration is a maintenance practice used to relieve soil compaction. In which seasons is it typically performed for cool-season lawns?

• A. Spring or fall to relieve compaction
• B. Summer only
• C. Winter only
• D. Any season, with no preference

Answer: (C)

Aeration works best when the lawn can quickly recover and push new roots into the loosened soil. For cool-season grasses, that recovery happens during active growth in moderate temperatures, so spring and fall are the ideal windows. In spring, the grass wakes up and soil moisture is often adequate, allowing the turf to knit the holes back together with new root growth. In fall, cooler temperatures and regular rainfall support rapid recovery and deeper root development before winter. Aerating in winter is ineffective because the ground is usually frozen or the grass is dormant, so holes don’t heal and the benefits are minimal; summer hot, dry conditions also hinder recovery. So, the best practice is to aerate in spring or fall to relieve compaction while the lawn can rebound efficiently.