Answer: There are a number of problems that can affect rhododendrons and then be carried on in the soil. I suspect this is one of them although based on your description I can't make a specific diagnosis. Often these problems will simmer until the plant is stressed (as it would be by hot and/or dry weather or by transplanting) and then appear. If this is true, since it is in the soil subsequent plantings would also be affected. You might wish to take a sample to your County Extension for a more definite identification of the problem and suggested controls. In the meantime be sure to clean up and destroy any debris from the plant to try to reduce the chances of reinfection. Good luck with your plant!
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