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Grubs in your lawn?

a guide for lawn care professionals and homeowners

Should you treat?

If your grub counts exceed the damage thresholds, you might want to consider treating for them. Your decisions will depend on when you find the grubs. If treating, target only the areas where grub populations exceed the suggested thresholds, or you've had a bad history of grubs.

In August:
The grubs are still small and have not caused a lot of damage yet, and are more susceptible to insecticides. In New York State you could use beneficial nematodes, imidacloprid (Merit), or trichlorfon (Dylox)—these are listed from least to most toxic. Note that on Long Island, imidacloprid may only be used if applied by a certified pesticide applicator. In other states, clothianidin (Arena) and thiamethoxam (Meridian) may also be available, check with your local cooperative extension office.

In September:
It's too late to use most products. Beneficial nematodes or trichlorfon (Dylox) may be used.

In October:
It's too late, though trichlorfon (Dylox) may still be effective in the first half of the month.

Late October-July
It's too late to treat last year's population—attacking them is a waste of time and money. If you've had a history of high grub populations and/or damage on your lawn, you may want to protect your lawn for the upcoming generation by applying one of the newer, softer pesticides that are best applied preventatively. These can be applied most any time from May-July, and for New Yorkers include imidacloprid (Merit) and chlorantraniliprole (Acelepryn). Long Islanders must note that imidacloprid may only be applied by a certified pesticide applicator and they may not use chlorantraniliprole. In other states, clothianidin (Arena) and thiamethoxam (Meridian) may also be available. Check with your local cooperative extension office.

Always consult with your local Cooperative Extension office for legal and recommended practices and products.

Disclaimer: Please read pesticide labels prior to use. The information contained here is not a substitute for a pesticide label. Trade names used herein are for convenience only; no endorsement of products is intended, nor is criticism of unnamed products implied. Laws and labels change. It is your responsibility to use pesticides legally.