Rhododendron disease - Ask Extension
I have a rhododendron that has been doing well for 30 years. This year it's starting to show some signs of trouble. I cannot seem to find the issue on...
Knowledgebase
Rhododendron disease #923628
Asked January 14, 2026, 4:35 PM EST
I have a rhododendron that has been doing well for 30 years. This year it's starting to show some signs of trouble. I cannot seem to find the issue online. I'm hoping you can help and tell me what's going on and if a simple fungicide is what's needed.
Washington County Oregon
Expert Response
Not really enough information to give a definitive diagnosis. I see a shoot that has dehydrated and died in your image. It just means the issue is further back on the stem or branch. How much further is unknown. You will have to look more carefully down the branch. I suspect you find a section that transitions from diseased to healthy. That is where you can make a pruning cut and dispose of the unhealthy portion.
