Pest Control
Grub Control: How to Save Your Lawn from Grubs
Emily WatsonPublished
What Are Lawn Grubs?
Grubs are the larval stage of beetles like Japanese beetles, June beetles, and European chafers. They feed on grass roots just below the soil surface, causing brown patches that lift like carpet.
Signs of a Grub Infestation
- Brown patches that pull up easily — roots have been eaten away
- Increased bird activity — birds digging for grubs in your lawn
- Spongy feel when walking on the grass
- Raccoon or skunk damage — animals tearing up turf to eat grubs
When to Treat
The best time to control grubs is late summer to early fall (August–September). Larvae are small, actively feeding near the surface, and most vulnerable to treatment. Spring treatments target larger, deeper grubs and are less effective.
Chemical Control Options
Preventive: Products containing chlorantraniliprole (GrubEx) applied in May–June stop eggs from hatching. One application protects for a full season.
Curative: Trichlorfon (Dylox) or carbaryl kill active grubs within 24–48 hours. Best for severe infestations discovered in late summer or fall.
Natural Control Methods
- Beneficial nematodes (Heterorhabditis bacteriophora) — microscopic worms that parasitize grubs. Apply to moist soil in the evening for best results.
- Milky spore (Bacillus popilliae) — targets Japanese beetle grubs specifically. Takes 2–3 years to establish but lasts 10+ years.
- Reduce outdoor lighting — bright lights attract adult beetles that lay eggs in nearby lawns.
Prevention Tips
Healthy lawns tolerate some grub feeding without showing damage. Maintain proper mowing height, fertilize appropriately, and avoid overwatering — moist soil attracts egg-laying beetles. A thick lawn with deep roots recovers faster from minor grub activity.
How Many Grubs Is Too Many?
A few grubs per square foot is normal and actually feeds wildlife. Treatment threshold is 10+ grubs per square foot in a healthy lawn, or 5+ per square foot in stressed turf. Dig a 1-square-foot section of damaged edge and count before deciding to treat.
