If you're seeing irregular brown patches that don't green back up no matter how much you water, or turf that pulls up like loose carpet with no roots holding it down, white grubs are a likely cause — especially through late summer, when they're actively feeding on grass roots just under the surface.
What grub damage looks like
Watch for irregular brown patches that don't respond to watering, or turf that pulls up easily like loose carpet — both are signs of white grub damage. It's easy to mistake this for plain drought stress, since both can start as a patch that won't green up. The giveaway is the roots: drought-stressed grass still has them, grub-damaged grass doesn't.
Why this matters
Grub damage often gets misread as drought stress, and checking for it now — before fall aeration and overseeding — matters for a specific reason: aerating and overseeding over an active infestation wastes the investment, since new grass roots just become the grubs' next meal.
Preventive vs. curative — and why the difference matters
The product you need depends entirely on timing, and this is where most people waste money: if you're seeing real damage right now, you need a fast-acting curative insect killer, not a season-long preventive product — a preventive formula has to go down before damage starts in order to work. Preventive products, by contrast, belong down in early summer, before grubs hatch, while they're still small and vulnerable — applied later, once damage is visible, that same product won't act fast enough to help.
What to expect
Treated (curative) areas should stop showing new damage within a couple weeks, but existing dead patches won't recover on their own — those spots need overseeding to fill back in. Preventive treatment, on the other hand, doesn't show a visible result at all — success looks like reaching late summer with no damage to report, not a visible change right after applying it.