What core aeration does
A hollow-tine machine removes small plugs from the soil. This can relieve compaction and improve movement into the root zone. Spike tools make holes without removing a core; they do not perform the same operation. Aeration is not a guaranteed cure for drainage, moss, weeds or lawn disease.
Decide whether the lawn needs it
Compare a worn route with an unworn area under similar soil moisture. Inspect rooting and soil firmness, and note standing water. Compaction can justify aeration, while shade, a low spot receiving runoff or unsuitable soil depth may require another response. A healthy lawn does not automatically need this job every spring.
Use the grass’s recovery window
Cool-season lawns are commonly aerated in early fall or suitable spring conditions, following local guidance. Warm-season lawns generally recover best during active warm growth after green-up. Avoid frozen, saturated, dormant or severely drought-stressed turf, and leave enough favorable growing time for recovery. A month on a national calendar cannot make that decision.
Prepare before equipment arrives
Mark sprinkler heads, shallow irrigation components and other known obstacles. Arrange appropriate utility-location checks before work where needed. Soil should permit useful cores without smearing wet ground. Ask an equipment provider how to operate the machine safely on your site, including slopes and roots.
Coordinate repairs and weed prevention
If reseeding, match the seed and timing to your grass and site. Check any recent or planned preemergent herbicide label because establishment restrictions may apply. Continue species-appropriate watering and mowing as the lawn recovers; extra fertilizer is not an automatic requirement. See clay and compaction and standing-water diagnosis.
Sources and local guidance
University guidance supports the species facts and care principles here. Rates and dates in a regional source apply to that region; they are not national prescriptions. Use your local extension office for cultivar, soil-test and treatment decisions.