Cutting the top off the tallest branches will cause both the rhododendron and azaleas to bush out. Prune as soon as they finish blooming. They begin forming next years flower buds in late spring and early summer. Also, giving them more sun will keep them from growing so gangly. Shade yields tall gangly plants with fewer flowers. You can thin plants that are creating shade so the rhododendron and azaleas will get more sun and grow fuller and have more flowers.

Here is a link that might be useful: How to grow rhododendrons and azaleas.

Thanks Rhodyman, I took a look at your link. I'm unclear about how much to cut. There are not many leaves on each branch, should I cut the tops off and leave some leaves, or just cut all the green off?
Thanks, David

Hi David,
Cut it back to the height you want. Then next year, after it blooms, you will see where you have new branches and you can cut the old branches back even further. If you want a tall plant, then just cut the tops off and leave some leaves.

Any advice on the rhodo, pictured at the end of my photo link? Also, people forgot to mention that when pruning, using scissors, to keep your free hand away from the business end to avoid making a LARGE gash in your finger....
-David

David, in your notes with your photos, you mention you mulched with peat. Peat as a top dressing rather than used as a soil amendment will shed water when it has been allowed to dry out, repelling moisture away from the rootball of your shrubs. Not a good idea.

You have a real horizontal shape going on with the rhododendron that I suspect has been there for some time.
To my eye, it's not a bad shape for the site and to change it dramatically you would need to do a complete renewal pruning. Which would of course be up to you....or you could just shorten the 2 or three lowest branches that are near the ground.

Pruning rhododendron:
Growth buds on rhododendrons form in the leaf axils (where leaf joins stem). If you want to shape up your plant, make your cuts just above a rosette of leaves (with hand pruners, not scissors) and new growth will emerge from the dormant eyes there.

If you have to cut into a branch below any leaf rosettes, look for faint rings on the bark where there once were rosettes of leaves. If you look very closely you may be able to see small bumps which are growth buds under the bark. Make your cuts just above the rings so dormant buds below them will be stimulated into growth.

If you cant find any rings or dormant buds, make your cuts wherever you must in order to shape you plant; later, when new growth starts, go back and remove all stubs down to the new growth. Dormant buds should begin to grow with a month approx on smaller limbs, 10 weeks on heavier main stems.

Azaleas have dormant buds all along the stems just under the bark - not just at leaf axils. So make your cuts wherever you wish to achieve the shape you want.

My OLD rhododendron is obscuring my view and needs to be cut back a lot! I have five HUGE bushes and hope that using my electric trimmer could be the first step in cutting back the bush. Is this advisable? Then I thought I'd hand prune to make the bush look better. thanks.

Go with hand pruning. Hedge trimmers make a mess of rhododendrons. First, rhododendrons are slower growers so they won't hide a butcher job. Second, they need to be cut individually based upon where the branches are leafing out. And third, they can get dieback in areas where the branches are damaged.

Prune it soon or you will be removing next years flower buds.

Here is a link that might be useful: How to grow rhododendrons and azaleas.

ezmpt, just to emphasize what rhodyman has already told you, your hedge trimmers are going to tear bark. Torn bark offers a foothold for disease and insect problems - you want clean sharp cuts.

Read above the information on where to make those cuts.