White mold(?) in garden - Ask Extension
Hello, I have an odd white mold like powder growing on some of my plants. It feels a little crusty to the touch but not too bad. Any idea what it is o...
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White mold(?) in garden #944386
Asked September 06, 2026, 4:29 PM EDT
Hello, I have an odd white mold like powder growing on some of my plants. It feels a little crusty to the touch but not too bad. Any idea what it is or if it’s bad? Thanks!
Hennepin County Minnesota
Expert Response
Thank you for providing good pictures.
It looks like powdery mildew and it is very common on rudbeckia.
https://extension.umn.edu/garden-and-home/yard-and-garden/gardening-in-minnesota/yard-and-garden-problems/powdery-mildew-in-the-flower-garden
It looks like powdery mildew and it is very common on rudbeckia.
https://extension.umn.edu/garden-and-home/yard-and-garden/gardening-in-minnesota/yard-and-garden-problems/powdery-mildew-in-the-flower-garden
