Marianne's Response
Fighting powdery mildew on knock out roses
We have 3 knockout rose bushes, they are all blooming and just beautiful. There is 1 problem. The leaves on all 3 bushes look like somebody poured milk on them. None of them are even close to the other or even in the same flower bed. One got it then maybe a week later we noticed another one had it. Now its about 2 weeks later and I see today the third one has it. Do you have any idea what it is or what to do for it?
Thanks
Valerie
Posted by on May 30, 2014
Marianne's Response
It sounds like you may have powdery mildew, a fungus brought on my cool, damp weather or dry soil and high humidity. Remove the worst of the leaves, mulch the soil with wood chips and don't water from above as wet foliage spreads this disease. A fungicide spray will control the problem on the new growth. Make sure your roses are not stressed out by too much or too little water. The Knock Out roses are pretty tough and I suspect they will make a full recovery.
Keep growing,
Marianne Binetti
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