Hi all - I recently potted a new John F. Kennedy rose that is about 3.5 feet tall and has multiple canes with a few buds which are about to open. A lot of the leaves, especially at the top of the canes, are curling at the edges and have a white cast to them, which from my online research looks just like powdery mildew. What would be the best way to treat that in a potted rose? Should I remove all the infected leaves and cut back the canes, or try to treat it with fungicide first? It would be a shame to cut it back severely -- the bush has a nice upright shape and strong, healthy canes. Also, I read that neem oil shouldn't be applied when temps are over 90 degrees; does that mean it shouldn't be used in hot weather at all, or just not actually applied to the leaves when the temp is above 90? Thanks in advance for any assistance.
Rhonda Richmond, VA USDA Zone 7
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