Experts and BHG readers answer.
Grubs in a lawn
I am guessing that you are referring to Step 3 of the Four Step Scotts program? If so, then it does not control grubs. And that's fine, if you haven't had grub problems in the past. Save your money -- no need to treat if there's no problem. If there is, you'll know it by August when thin or dead patches start to show up. In that case, you'll know to treat for grubs next year with GrubEx (in early June). Bottom line: don't apply it