How to prevent/treat black spots on Hydranga leaves - Ask Extension
For the past four years our hydranga shrub has been plagued with black spots gaon its leaves. I have treat d with Neem fungicide and high reduced but...
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How to prevent/treat black spots on Hydranga leaves #874193
Asked June 22, 2024, 2:23 PM EDT
For the past four years our hydranga shrub has been plagued with black spots gaon its leaves. I have treat d with Neem fungicide and high reduced but not completely eliminate the spots.. What can I do to control these spots. See attached photos. Also, what is the variety/species that of the hyrdranga?
Washington County Oregon
Expert Response
Thank you for your question, Bill. OSU has identified both fungal and bacterial causes for hydrangea leaf spots: https://pnwhandbooks.org/plantdisease/host-disease/hydrangea-leaf-spots
Other sources have cited cercospora hydrangea leaf spot. We cannot diagnose which your plant has. I suggest that you submit plant samples to the OSU Plant Clinic for diagnosis: https://bpp.oregonstate.edu/how-submit-plant-materials
Good luck!
Other sources have cited cercospora hydrangea leaf spot. We cannot diagnose which your plant has. I suggest that you submit plant samples to the OSU Plant Clinic for diagnosis: https://bpp.oregonstate.edu/how-submit-plant-materials
Good luck!
