BattleWagon said:


My lawn looks terrible. Suspect grubs.
Could someone tell me when is the best time to apply the grubex in NW =
Pa.

The instructions say from April to mid August but the best time is right
before the eggs hatch, have no clue when that would be.

Per MSU IPM landscape CAT (April 18):

"In order to avoid the same problem next year, treat lawns with Bayer Advanced
Lawn Season-Long Grub Control or GrubEx (imidacloprid) in July. Note: these two
products will not work on large grubs that are present at this time (or next fall), but
they are excellent for control of the young grubs present in late July and early
August."

NW PA would not be too much different than southern Michigan, I think.
Mid-July would likely do for you.

I you can afford to provide enough supplemental water to keep the grass
actively growing all summer, you can keep it ahead of the feeding grubs.
Summer-dormant lawns take heavy damage from grubs.
--
Pat in Plymouth MI

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)