Fall Grub Control: Timing, Products, and Seeding Strategy

A New Jersey homeowner with a mid-September grub infestation asks: 1) Is the lawn permanently damaged? 2) Seed now or wait? 3) If permanently damaged, seed now and treat grubs next spring? 4) Product recommendations?

Fall Treatment Difficulty

Grubs are likely too large for curative products to work well. If treating now, use a contact insecticide (diazinon, isazophos, trichlorfon) and irrigate well to keep grubs near surface.

Seeding

You can reseed immediately after treatment.

Spring Prevention (Best Approach)

• Apply preventive product in April/May containing imidacloprid (Merit) or isazophos (Triumph).
• Examples: Bayer Advanced Season-Long Grub Control, Scotts GrubEx.
• These are NOT effective in fall; do not use them now.

Damage Assessment

If turf pulls up like carpet (no roots), it's dead. If roots hold, it may recover with water after grub control.