Grubs are only a problem following a heavy accumulation of beetles around your porch lights in the late spring. The old timers say if you see them one year you will not see them again next year. Don't know why.

I use beneficial nematodes for grub control but only after the heavy beetle populations are seen. Before you do anything you should dig around looking for them. If you find more than 12 per square foot, then apply something. Otherwise your soil should tolerate them. Beneficial nematodes bring a disease to the grubs which kills them in 24-48 hours.