advice on older deciduous azalea specimen
I have a GORGEOUS deciduous azalea that is the pride of my garden. I'm not sure what variety it is, though doing some research on the web, it look a lot like some of the Aromi hybrids, such as Aromi Sunrise. (But that's just a guess, as it was planted well before I bought the property. If I can figure out how to post a photo, perhaps someone can help me identify it more precisely.) Very nice stems with a Japanese garden look, and gorgeous orange flowers. My best guess is that it was planted around the same time the deck it borders was laid, around 1980.
As I say, I'm in love with this bush, and want to keep it healthy, and have tried (unsuccessfully, thus far) to get cuttings to root. Some concerns:
The past two summers, the leaves have developed a fungus around mid-summer that pretty much covers them by fall. It is a dark grey, perhaps with hints of rust color. It is unattractive, but thus far the leaves have come back each spring. I've tried Safer Soap on the advice of a consulting master gardener, but it did not seem to help.
This year, the crop of flowers on this bush was sparse compared with previous years. (My other azaleas bloomed about the same as other years.) The blooms were all on top, starting at about 6 feet. (Leaves start at about 4 feet.) It MIGHT be the work of deer, which did a number on one my evergreen azaleas, but I see no other signs of deer damage to this plant.
I would like to prune the branches that are straying onto the porch, but have read that with an older plant, one should cut back only one major branch per year.
An arborist who was on the property seemed to think that the plant was nearing the end of its lifecycle and I'd only have a few more years with it. She knows far more than I, of course, but to me it looks like a healthy plant when its leaves are not spotted.
What should I be doing to make sure this specimen azalea lasts a long time?