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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Basic human psychology is one of my subroutines.