Don’t worry about grubs in the vegetable garden. If you see them just step on them to kill them. Early in June they turn into Japanese Beetles and you can spray for them then if they seem to be a big problem. The lawn, if it is healthy can withstand up to 4 grubs per square foot. If the lawn is suffering from the grubs then you should start treating every July…the grubs you have now hatched last year. Here’s a blog post all about grub control