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Hydrangea fungus #929682
Asked April 26, 2026, 2:46 PM EDT
Olmsted County Minnesota
Expert Response
This is a poisonous mushroom. They can signal a fungal infection. I would cut out the infected stems and dispose of them. The fungus is usually caused by too much moisture. Remove the mulch under the plant and check for fungus underneath. Move the mulch away from the stems of the plant and allow air to get to them. Keep an eye out for more and apply a copper-based or neem oil fungicide to the affected area if it comes back. Good luck!