I have a few overgrown rhododendrans at the perimeter of the yard that are in need of trimming. When is the best time to trim them and how much do you trim???

Given that they haven't been trimmed in who knows how long, the insides are pretty bare and just flowers and leaves on the outside - - do I trim back to encourage growing in??? They aren't huge, just out of shape and lacking alot of foliage.

The best time to prune rhododendrons is just after they bloom. Fall or winter pruning removes next year's flowers. Trimming your rhododendron back will make your bushes more compact, fuller and probably produce even more flowers over the next few years. Make pruning cuts at an angle, just above a bud.

pshew.....I had already trimmed a couple of them and wasn't sure - - sounds like I made it in the "nick" of time.....