Steven, An important factor in successful grub control is application timing,rate and pest being controlled. If Merit
is applied to early there will be not enough residue for effictive control. Bayer is recommending applying Merit at the highest rate. Merit should be watered in very soon after
the initial application v/s Mach 2. Was the grubs found checked to see what grub it was? If the grub was a masked
cheafer you may have missed the window. I've used Merit for the 5 years or so and have had excellent results. No plans
on changing products any time soon. By the way I use granular fertilizer w/ Merit.