problem with my azaleas dying

Question

I have a gentle bank of azaleas in my backyard. Some have been there 18 years. While they continue to grow and flower each year, I have been losing a lot of branches from them in the last few years. They are not thick like they used to be. There is no sign of bugs or fungus. Is there something I can do to get them back to healthy looking plants? They look so spindly now.

Answer 1

Just in case, check this article for signs of botryosphaeria disease:
https://www.gardeningknowhow.com/ornamental/shrubs/azalea/azalea-branches-dying.htm

Also, the borers described in the article and in the following article would be inside the branches, so the presence of insects wouldn't be obvious from the outside:
http://extension.umd.edu/learn/ipm-series-azaleas-and-rhododendrons-hg51

Another possibility is that the azaleas are unhappy in their current conditions- for example, perhaps the soil pH is too high or they are in excessive sun, especially if something in their surroundings has changed in the last few years.