What Lawn Grubs Are
Lawn grubs are the larvae of beetles such as June bugs, Japanese beetles, and chafer beetles. These C-shaped, white larvae live beneath the soil and feed on grassroots, causing large patches of dead or thinning turf. If you’re unsure whether the symptoms you’re seeing match grub activity, compare them using the Pest Symptoms Index.
Early Signs of Lawn Grub Damage
Grub damage often goes unnoticed until the turf begins to decline. Look for these early indicators:
- Brown or thinning patches: Areas that look drought-stressed despite watering.
- Spongy turf: Grass that lifts easily from the soil due to root loss.
- Increased animal activity: Skunks, raccoons, and birds digging for grubs.
- Wilting grass: Even with adequate moisture.
For more general pest questions, visit the FAQ page.
How to Confirm You Have Lawn Grubs
To verify grub activity, perform a simple soil inspection:
1. Cut a Square of Turf
Use a shovel to cut a 1-foot square section of turf and peel it back.
2. Count the Grubs
Finding more than 5–10 grubs per square foot typically indicates an infestation.
3. Inspect Root Damage
If the roots are chewed off and the soil contains C-shaped larvae, you’re dealing with lawn grubs.
For broader pest identification help, check the Start Here guide.
How to Eliminate Lawn Grubs
Once confirmed, act quickly to prevent further turf damage. The most effective treatments include:
Use Preventative Grub Control (Spring/Early Summer)
Products containing chlorantraniliprole are highly effective at preventing grub development.
Use Curative Grub Control (Late Summer/Fall)
For active infestations, use products containing carbaryl or trichlorfon. These provide fast knockdown of existing grubs.
Water After Application
Most grub treatments require watering to move the product into the soil where grubs feed.
Use EPA-Approved Products
Always choose treatments listed by the EPA for lawn pest control:
EPA Safe Pest Control
How to Prevent Future Grub Damage
- Apply preventative grub control annually
- Maintain healthy, well-watered turf
- Reduce thatch buildup
- Monitor for beetle activity in summer
With early detection and proper treatment, you can stop lawn grubs before they cause widespread damage.