Common in summer
Grubs in the Lawn: Signs and How to Check
Grubs are beetle larvae that chew grass roots below the surface, leaving patches that brown out and can be rolled back like loose carpet. They're a common late-summer cause of dead patches — but only worth treating when you actually confirm enough of them, so a quick count comes before any product.
How to tell
- Irregular brown patches that feel spongy underfoot because the roots are severed.
- Turf that peels or rolls back easily, with no anchoring roots underneath.
- Skunks, raccoons, or birds digging up the lawn at night to eat the larvae.
- White, C-shaped larvae in the top inch or two of soil when you peel back a patch.
What to do
- Step 1
Cut a flap and count
Peel back a one-foot square of turf at the edge of a damaged patch and count the white, C-shaped grubs. A few are normal and harmless; control is generally only warranted when counts run high (often cited around 8–10+ per square foot for many grasses).
- Step 2
Support recovery first
A healthy, well-watered lawn outgrows light grub feeding. Keep it watered and mowed high so it can repair the root damage on its own where counts are low.
- Step 3
Treat only a confirmed infestation
If the count is genuinely high, choose a product labeled for grubs and match it to the timing on the label (curative vs. preventive products work at different life stages). Reseed killed patches in the fall.
Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.
Preventing it next season
A deep-rooted, properly watered lawn tolerates grubs far better than a stressed one. Where grubs are a yearly problem, a preventive product applied at the labeled time is more effective than chasing damage later.
Frequently asked questions
- How do I know if I have grubs or just drought?
- Drought-browned grass stays rooted and perks up with water; grub-damaged turf lifts or rolls back because the roots are chewed off. Peel back a patch edge and look for white, C-shaped larvae to confirm.
- How many grubs are too many?
- A few grubs per square foot are normal and don't need treatment. Damage usually only shows up at higher counts, so do a one-square-foot count before treating, and follow the product label for the threshold and timing.