After quite a few comments on pruning the rhodies, I want to better explain what has already been done and what is left to do.
I left the loppers and my brand new pruning shears out on top of the heat pump yesterday, and it rained on them all night :-(
First all dead wood was removed. Then I took off as many crossing branches as I could, although many are quite twisted and crossing toward the main trunk. I think there is one large secondary trunk that can now be removed, as it has very few leafy branches on it. It will require bringing out the chain saw.
This, the larger of the two bushes, had finished flowering (at that half-dead flowers stage). I always snap the spent blossoms off at this time, making sure not to injure the new growth just below the flower. That's one thing I have actually done correctly over the past twenty years!
Next I cut back each branch to new growth, where the growth was pointing upwards. Each of these branches has a whorl of leaves that will blossom next year.
So far, so good.
Now comes the problem. If I remove anything but the new growth at the top, I'll have to cut right into bare wood.....no growth of any kind coming from them. I can't see leaving bare stubs sticking up, so this means all I could do is control future growth in height, not bring down its present height.
My previous neighbor, Pat, had a huge rhodie that was cut nearly to the ground last year, and it is up and blossoming again. Maybe I'll go look at it and see if it was cut back to bare stubs.
Pruning and Deadheading Rhododendrons
This tells me I am pruning it at the correct time, which was a concern of some:
If a plant grows out over a walk or needs to be restricted for some reason, it may be pruned back moderately without fear that the plant as a whole will be damaged. It is often possible to do this pruning during the blooming season and have flowers for the house. Light maintenance pruning at the time "dead-heading" is done (see below), can help keep the plant in shape. Light to moderate pruning done at the time the plant is flowering or immediately thereafter will not affect flower bud formation for the following year.
And this tells me it's probably OK to cut it down to stubs on the top, but it won't be very pretty next year.
Old leggy plants may need pruning, but often these are better replaced with smaller newer varieties. Old plants, however, can be cut back severely and still recover, although it may be a while before they bloom again.