Here is a link to the first picture

http://photos.gardenweb.com/garden/galleries/2009/03/rhods1.html

Compost and mulch will help both plants a lot. If you don't make your own compost, you can buy bagged compost at Home Depot, etc. - mushroom compost and composted cow manure are the two kinds. Pine straw, pine chips, hardwood chips (nothing colored) - all of those good organic mulches help keep the ground cool in summer, retain moisture and keep most weed at bay. Organic compost also attracts beneficial critters like worms and beetle whose by-products enrich the soil.

These products both naturally acidify the soil, so no need for vinegar (I've never heard of using that).

I'm sorry but that link does not work for me.

Do you know when the rhododendrons were pruned? If cut back hard, it could take them a couple of years to recover and begin to bloom again.

Other than that, number one reason for failure to bloom is too much shade. You say 'shady', they appear to be in reasonably bright light in your photo. Do you know approx how many hours of sun per day they get? Could trees have grown up around them or has something been added to the garden where they are now in more shade than they were in the years the neighbors tell you they bloomed well?

Number two is too much fertilizer - these are not heavy feeders and fertilizer (particularly fertilizers heavy on nitrogen) will cause foliage growth and no blooms. It doesn't sound like you've had anything to deadhead, but rhododendrons are also prodigious seed setters and the formation of seed can take energy from the plant that would otherwise go to formation of flower buds....buds that are set in late summer. Drought in late summer can alter flower bud set too.

Wish you had a photo of the azaleas, but quit with the vinegar, there is nothing beneficial there :) As for fertilizer, they have the same low nutritional requirements as the rhododendrons - the advice above to mulch and keep watered was good, in acidic soil of average fertility they may need nothing else.

I'd strongly advise against using bagged composted cow manure for rhododendrons (too much nitrogen and too alkaline) or anything else. These products - not all, but many - come from feedlots. They tend to be highly alkaline, contain a great deal of very fine soil which repels water when it dies out, and frequently contain high levels of salt and other undesireable chemicals.

The rhododendron leaves look extremely healthy. Lack of acidity doesn't seem to be the problem. Fertilizing and shade seem to be the prime candidates.

I think fertilizing is the main problem. Nitrogen creates healthy leaves but discourages blooming. Don't fertilize until they start blooming and if you do fertilize after they start blooming, only use something like HollyTone that is low in nitrogen.

Shade will definitely prevent flower bud set. Cut back any low branches that cause shade. Your pictures make it look like you have an almost ideal high shade situation with a fair amount of sun getting through.

The azaleas are another story. Do you have deer problems? Deer love azaleas and will defoliate them like yours look. There are a number of repellents, but I find that using deer netting in the winter works much better.

If the azaleas were fertilized, they will stop blooming the same as the rhododendrons.

If an azalea or rhododendron needs more acidity or is otherwise having nutrient problems, its leaves will be yellow with green veins. I didn't see that on any of your plants. Your photos of the azaleas were not as close so it was hard to tell for sure.

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

Here are answers to the questions.... Sorry, I do not know how to insert a picture. But if you click on galleries and search for peppernc, there are photos of azaleas and rhods....

Q1.Do you know when the rhododendrons were pruned?

These beautiful plants were chopped down about three years ago. Also, I fed them with Azales/Rhods specific food. I put holes in the ground about 3 inches in diameter and four inches deep and filled with proper food about 8' diameter around the base. The new three feet or so of growth came from this care and feeding. Upon closer inspection it looks like I will have lots of blooms this year.

Q2. Shade/Sun
They get about 4-6 hours of sun in the afternoon. The trees around them are 80-90 ft tall pine trees. The bottom 2/3rds of the pine trees are clear.

Q3. Deer problems with Azaleas (bingo)
The Azaleas in the front yard, yes deer are the answer. Deer are everywhere all year around. That's exactly what these look like. I have decided to pull them and plant something less deer friendly.

Thanks so much for the help folks.
I am doing the right thing for the rhods and the deer help me with my sorry azaleas.

I did finally see the picture of the Rhododendron and it looks very good.

Good luck!