When should I put roundup around my lawn and shrubs
According to experts at the University of Minnesota, "the best time to apply insecticides for grubs is from mid-July until early September. Granular applied insecticides distributed on soil with a spreader are usually the best insecticides for Japanese beetles."
Don't apply a grub control product unless the lawn has been damaged and grubs are actually found beneath the turf in significant numbers. If control is needed, limit applications to the lawn.