Late freezes after a warm winter/early spring caused a good deal of damage to rhododendrons and azaleas wherever such conditions occurred. Wilting such as the photos show was one symptom of the damage - as if the plant were no longer capable of moving water through its stems. Why this would have occurred in just one of the Mandarin Lights is a mystery. Perhaps excessive wetness or poor drainage in this one spot is a contributing factor. A "couple of tosses" of both 10-10-10 and Holly Tone is way too much fertilizer and could well have burned the roots also.

"A "couple of tosses" of both 10-10-10 and Holly Tone is way too much fertilizer and could well have burned the roots also."

LOL, As you know nothing of my hand size or my tossing technique this is absurd. Clearly not the issue here. Nor is drainage.

Next?

I think akamainegrower makes a reasonably valid point. That's a small plant with a small rootball and it wouldn't take too much fertilizer to harm it. It could also dry out very quickly. The two together can even make it more susceptible to damage.

I'm not going to venture a guess on the larger plant because I've never had a freeze on new growth before. The symptoms appear different than the small plant is experiencing.

Mike

"LOL, As you know nothing of my hand size or my tossing technique this is absurd. Clearly not the issue here. Nor is drainage."

Since you didn't give us any detailed info about your hand size or soil texture, it wasn't absurd IMO. Rhodies (and that includes azaleas) rarely if ever need fertilizer IME. I give mine a good layer of organic mulch, and that's it. No fertilizer ever, and they bloom and grow well. I have several different plants in the Lights series, and the only one that hasn't done well is the one DH ran over with the brush hog. Depending on your 10-10-10 solubility, amount of rain, evenness of distribution, and depth of mulch there is potential for harm since all rhodies are quite shallow-rooted, more so than most other shrubs.

Is there anything else that is different?

Here it's been dry, and that can cause stress.

Is this plant slightly higher or lower than any of the surrounding plants?

Is it closer to other plants than the other azaleas?

Do you have any others of this same cultivar?

Do you have critters that might be effecting the roots such as chipmunks or voles which cause untold damage in my gardens, though they seem to avoid the rhodies. (I am looking at what seems to be a hole between the roots of the nearby tree.)

Has anyone used weed-n-feed on a nearby lawn area or any other herbicides that might have drifted or washed into the root zone of the plant?

Can you add a photo of the wider area in case there is something else that might be apparent?