How to Kill Grubs

Do the tug test on brown patches. If grass pulls up with no roots, peel back a 1 sq ft section at the edge of the damage. Count grubs: more than 5 per sq ft warrants treatment. If you find fewer than 5, the damage may be from drought or disease, not grubs.

Trichlorfon (Dylox 6.2 Granular) is the fastest-acting curative: kills grubs within 24 to 48 hours. Chlorantraniliprole at curative rates also works but takes 1 to 2 weeks. Apply at the rate on the label, typically 4.6 lbs per 1,000 sq ft for Dylox.

Spread the granular product with a broadcast spreader, then water in with at least half an inch of irrigation immediately. The product must reach the grubs in the root zone (top 2 inches of soil). Without watering, it won't contact the grubs.

Give the grubs time to die and the product time to dissipate. After 2 weeks, rake out the dead grass and thatch in damaged areas, loosen the top half inch of soil, and overseed at the standard rate for your grass type. Apply starter fertilizer and keep the area moist for 2 to 3 weeks.

Curative treatment means the prevention window was missed. Set a calendar reminder for May to apply preventive grub control next year. Annual prevention costs about $15 per 5,000 sq ft. Curative treatment plus lawn repair costs $50 to $100+ for the same area.