Hi MrsD, you need to use a diazanon spray which you should be able to find at your local garden center. This normally is applied in late year (i.e., Sept/Oct), but you may have "some" luck if you apply prior to your grass greening. The reason that it is normally applied late in the year is that grub worms (larvae) are young June bugs (beetles) and toward the end of their adult life (late summer) they lay their eggs in your yard. So applying the diazanon after they have layed their eggs will kill them when they hatch in the spring, so if you can soak the yard prior to the eggs hatching you should have some luck. Hope this helps, and good luck!