Problem with azalea bush

Asked April 6, 2020, 4:16 PM EDT

My name is Shirley Parker, I have an Azalea bush that is at least 25 years old and is very large, the branches has a white substance on them and some of the branches are brittle, some leaves are brown or have brown spots, bulbs are present but appear to be stunted and unhealthy, the white substance resembles powdered sugar, except it will not rub off. I am hoping that it maybe just a fungus, parasite or some other infectious agent that is treatable. I would hate to loose the bush, if you could diagnose the problem and recommend a treatment, I would be most grateful, I am pleading for help. Thanks

Jefferson County Kentucky

1 Response

It is difficult to ID problems with photos only but I can tell you what I see. There appears to be a massive scale infestation causing the white crusty "stuff" you see. the best control is to prune out as much of the affect growth as possible. Spraying with an insecticide alone is not enough. After you prune, spray with insecticidal soap according to label instructions on scale control.

Lace bug may also be a problem. These insects are summer feeders so are not present now. Link to control:

I also suspect the soil pH is too high making the leaves appear chlorotic. Azaleas need an acidic soil so a soil test can help you there. Our website has that information here:
The soil test results allow us to recommend what nutrients and pH adjustments are needed for azaleas.

Please let me know if I can help you further.


Carol Wilder

Horticulture Technician

Jefferson County Cooperative Extension Service

4200 Gardiner View Ave. Suite 101.

Louisville, Ky 40213


Fax 502-569-1680