Aeration and dethatching: does your lawn actually need it?
Aeration gets sold hard every spring, but not every lawn needs it every year. Here's how to tell — and how to time it so it actually helps.
The screwdriver test
Push a screwdriver into moist soil. Slides in easily? Your soil isn't badly compacted. Takes real force? Compaction is choking roots, and core aeration — pulling plugs of soil — will open things up for water, air, and fertilizer.
Thatch: the half-inch rule
Cut a small wedge of turf and measure the brown spongy layer between green blades and soil. Under half an inch is healthy (it insulates and cushions). Over that, water and nutrients start bouncing off — time to dethatch or aerate aggressively. And no, clippings aren't the culprit; see our mulch-or-bag post.
Timing matters more than method
Cool-season lawns (Chicagoland): early fall is ideal — the lawn heals fast and you can overseed straight into the holes. Spring works; summer doesn't.
Warm-season lawns (Texas): late spring through early summer, when Bermuda and St. Augustine are growing their hardest.
Afterward
Leave the plugs on the lawn — they break down in a couple of weeks and recycle nutrients. Water deeply, fertilize if you're due (see our Illinois fertilizer schedule), and keep mowing on rhythm.