What is causing the leaves on my azalea bush to have a strange color and not produce many flowers?
Question:
My azalea bush is about 30 years old and has bloomed beautifully every spring around Mother’s Day. Last year there was very few flowers and this year the leaves are a weird color and I have no idea if it will bloom. It does not get too much water. I’ve looked up pictures and I don’t think it is a fungus. Maybe something to do with the soil?
Answer:
We would need to submit a sample to a diagnostic lab to be 100% certain, but you’re almost certainly dealing with either lace bugs or spider mites. Both are well-known pests on azaleas, their damage appears similar (stippling of the leaves), and both can be a bit tricky to get rid of. Spider mites will leave tiny masses of webbing under the affected leaves and down in the axils of leaves and branches coming off the main stem–it’s pretty apparent if you look for it.
Clemson Univ page on Azalea pests
Clemson Univ page on Lace Bugs
Clemson Univ page on management of Spider Mites
The resources listed above provide information on the ID and life cycles for both pests, how they persist on the plant, and how to control them. Lace bugs will lay eggs in the leaves and protect them with a hard, resinous cover, but if worse comes to worst and the attempts to control aren’t effective, the good news is that most rhododendrons and azaleas are tough plants and can withstand serious cutting back to remove all the infected tissue. That may also be your option if you’re uncomfortable with chemical controls, though be advised that it may interfere with the plant’s bloom cycle for a year or two. It should recover.