I have hardy roses in my Minneapolis backyard. The leaves have large sections...

Asked June 16, 2015, 7:22 PM EDT

I have hardy roses in my Minneapolis backyard. The leaves have large sections that are brown, but they are transparent. I have 5 bushes and they all have them. They are flowering, but the plants don't look healthy. Can you help?

Hennepin County Minnesota

1 Response

This looks like powdery mildew:
http://www.extension.umn.edu/garden/yard-garden/flowers/rose-diseases/#powdery-mildew

Powdery mildew is a common fungal infection of roses in Minnesota. Treatment is prevention: good sanitation and proper watering. Many people treat their roses in the spring with fungicides - powdery mildew is just one in a long list of fungal infections that roses are susceptible to.