This rhododendron is 25 years and was well settled in its environment. However, last year it started shedding a lot of its leaves, which were curling and it looks like it is dying. Can I do anything to revive it? If I prune it, will it grow back? Should I leave the dead branches alone or cut them off? Does new growth come from the hard wood branches?
The symptoms you describe sound like winter burn, which is mentioned in the following article:
I would follow the watering and fertilizing guidelines in the following article:
Rhododendrons bloom on old wood. Rhododendrons set buds in late summer, buds that overwinter and then burst into bloom in spring. Pruning is best done after flowering in late spring. And, yes, you will want to prune those dead branches.
For pruning guidelines, please visit the following article: