Hydrangea fungus on leaves - Ask Extension
We have a 10 foot hydrangea bush. The leaves get a white powdery stuff on them in the spring.
What can I spray on them to prevent this and when shou...
Knowledgebase
Hydrangea fungus on leaves #846668
Asked August 21, 2023, 3:56 PM EDT
We have a 10 foot hydrangea bush. The leaves get a white powdery stuff on them in the spring.
What can I spray on them to prevent this and when should I spray it?
Hennepin County Minnesota
Expert Response
I can’t tell what the white blobs are. To attempt identification a crisp, high magnification photo is needed.
A sample can be sent to the plant disease clinic and they will be able to tell you what it is.
https://pdc.umn.edu/
If it is powdery mildew, although it doesn’t look like it …
https://extension.umn.edu/plant-diseases/powdery-mildew-trees-and-shrubs
Powdery mildew can be reduced with cultural changes.
A sample can be sent to the plant disease clinic and they will be able to tell you what it is.
https://pdc.umn.edu/
If it is powdery mildew, although it doesn’t look like it …
https://extension.umn.edu/plant-diseases/powdery-mildew-trees-and-shrubs
Powdery mildew can be reduced with cultural changes.
