5 Signs of Grub Damage (and What to Do About It)
How to spot grub damage before it kills your lawn, plus the exact treatment windows for preventative and curative grub control.
Grubs are the larvae of Japanese beetles, June beetles, and chafers, and they can destroy a lawn in weeks. Most homeowners spot the damage only when it is too late. Here are the five signs to watch for.
1. Irregular brown patches
Unlike drought stress, which shows gradual yellowing, grub damage looks like irregular brown blotches that appear within days. They feel spongy underfoot.
2. Grass peels up like loose carpet
This is the dead giveaway. Grubs eat grass roots, so the turf loses its anchor. Pull up a section. If it lifts like a rug, you have grubs.
3. Increased digging from wildlife
Skunks, raccoons, and crows love grubs. If these animals are suddenly tearing up your lawn, they are hunting, and your lawn is the buffet.
4. Visible grubs when you dig
Peel back a section of damaged sod and look at the soil surface. Grubs are white, C-shaped, about the size of your thumbnail. More than 5 to 10 per square foot usually means it is time to treat.
5. Damage peaks in late summer or fall
Grub damage usually shows up in August through October, when larvae are at their largest and most destructive.
What to do
- Preventative treatment in late June or early July stops hatching. This is the most effective long-term strategy.
- Curative treatment in late summer or early fall can save remaining turf if damage is already visible.
- Reseed dead patches after treatment. Do not skip this step.
Related reading
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