Question
I live in Cincinnati and just planted a nice size Knock Out Rose bush purchased from a well known nursery (note:expensive).  After planting it, we noticed a ton of black caterpillars in our yard.  Unfortunately, the rose bush has been stripped clean.  Will the leaves ever grow back?

Answer
Roses can put out three sets of leaves before the effort starts to make the plant weak. I would give your rose a light pruning so it doesn't have to replace as many leaves. Starting from scratch does require effort. Also if you haven't fertilize the rose now would be a good time.