Osmocote is a slow release fertilizer so you don't need to apply any more. You probably have way too much. Once in the spring at half the rate on the package is all you need. I hope it is the Azalea, Camilia, Rhododendron version of Osmocote. Also, I hope you didn't follow their directions:

"1. Sprinkle evenly across areas to be fed"

This is OK. It is basically inside the dripline of the plant.

"2. Mix into top 1 to 3 inches of soil or mulch"

Don't do it. Rhododendrons have shallow roots and you can't cultivate the soil without harming the roots. That is why a mulch is important to keep down weeds, keep the roots cool, and conserve moisture.

"3. DonÂt forget to water regularly"

Don't. Only water when they need it. Too much water and poor drainage are the biggest killers of rhododendrons.

"4. Reapply every 4 months"

Don't. They don't need it even though Scotts, the makers of Osmocote, would love to see you do it. Once in the spring at half the rate is plenty. If the leaves turn yellow with green veins, that is a sign that there is a problem in the nutrient balance. This includes: lack of acidity in the soil, potassium deficiency, calcium deficiency, iron deficiency, magnesium deficiency, nitrogen toxicity (usually caused by nitrate fertilizers) or other conditions that damage the roots such as root rot, severe cutting of the roots, root weevils or root death caused by extreme amounts of fertilizer. In any case, a combination of acidification with sulfur and iron supplements such as chelated iron or iron sulfate will usually treat this problem.

As I mentioned in your other post, too much shade can be a problem. Pruning in the spring just after blooming is the best time and you can do severe pruning.

Rhodyman has a guide to pruning on his website that gives specifics of where, when, and why to prune. One of the key points is that if you are going to prune severely (I have pruned salvaged plants from a dump pile to about 10 inches) the plant needs to be in enough sunlight if if is going to recover. There are buds under the bark that will sprout if the plant is in good health and gets enough sunlight. Read the guide and repost if you still have specific questions. You can prune later than he recommends if you don't mind forgoing blooms for a year.

Here is a link that might be useful: Rhodyman's Rhododendron and Azalea pages

Nice Site Rhodyman! I bookmarked it. I have all kinds of new Rhodies & Azaelas to baby this summer. I am brand new to Rhodies. Your guide will sure come in handy. Thanks nhbabs for the recommendation!