We are seeing multiple deaths of our rhododendrons in our yards after seeing spots on the leaves which then turn yellow and brown. We have lost five plants over the last couple of years and I am afraid that it might be spreading to other broadleaf evergreen shrubs.
Clackamas County Oregon plant disease
More information about how the plants are grown is needed. What watering? Any changes over the past years? Mulch? Tree removal changing sun? All of these issues need to be considered. How long have you owned the property? Photos from a greater distance may help. Also a closeup of the bark.