Aerate fescue in the Triangle between September 15 and October 15. Not spring, not summer. Fescue is a cool-season grass, and fall is the only window where aeration and overseeding get three cool months of recovery before the lawn has to survive anything hard.
Here's the problem aeration fixes. Most lawns in Apex and Cary sit on compacted red clay. Water runs off instead of soaking in, roots stay shallow, and by mid-July the lawn browns out early no matter how much you irrigate. A core aerator pulls 2 to 3 inch plugs out of the soil and drops them on the surface. The plugs break down within a couple of weeks and the holes give water, air, and seed a way down to the roots.
Overseed the same day, every time. Run 5 to 6 pounds of tall fescue seed per 1,000 square feet right behind the aerator while the holes are open. Fescue doesn't spread sideways the way bermuda does - a thin spot stays thin until seed goes down. Water 10 to 15 minutes twice a day for the first two weeks, then switch to two deep waterings a week once the new grass is up.
Two mistakes we see every year. First, spring aeration: it opens the soil right as crabgrass germinates, so you're planting weeds. Save it for fall and put down pre-emergent in spring instead. Second, aerating dry ground: the tines bounce off Wake County clay in a drought. If it hasn't rained, run the sprinklers the night before.
We run aeration and overseeding for $225 on most quarter-acre lots, seed included, and the September calendar fills by mid-August. Call or text (919) 555-0187 and we'll put you on the list.