Hi, I am a newbie here. I've been growing rhododendrons for quite a few years but never got hit with such heavy snow and frost like this before. I have 2 that have grey limbs, dead foliage and spots on the old leaves that are still green. New leaves are popping up but what do I do to nurse them back to their previously lush greenery? They look soooo sad! Please offer some advice! Thank you!