Roses forum→Powdery mildew?

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Name: David Tillyer
New York City (Zone 7b)
May 31, 2020 2:58 PM CST
Is this a case of powdery mildew? My wife has miniature roses on our 37th floor balcony. The wind is pretty
vicious, but this bush made it through the winter without much covering. But now it has spots of this
white powdery stuff...powdery mildew? I can't imagine actual mildew living in a windy environment. Perhaps
rose powdery mildew is a different kind of mildew. My wife has been treating it with Neem oil. Does that
sound right? I've read warnings about using it in sunny about sunny, windy spots? David

Thumb of 2020-05-31/BigAppleRoseGuy/233592

I couldn't take a picture outside because the windy had everything blowing around. So I clipped a sample.
Coastal Southern California (Zone 13a)
May 31, 2020 5:01 PM CST
Of course, I'm not in N.Y., and not on a balcony, but . . . Yes. That is powdery mildew.

Yes, neem oil is often recommended for it.

FWIW, I have had neem (and other oils ... oil is oil, after all) burn foliage to a crisp in a high temperature of 75 deg. Your Mileage May Vary. I found that uglier than the mildew.

How large is the pot? How large is the plant? Is it getting plenty of water? Sometimes, roses are more likely to mildew when they are under stress.
Name: David Tillyer
New York City (Zone 7b)
May 31, 2020 5:32 PM CST
Good point, Jeri. We will watch the watering. I think that constant wind and, perhaps under-watering constitutes stress.
You're a real help.

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