Question
Hello, I just planted a "Knockout rose" shrub rose 5 days ago. It was a little droopy for the first two days then perked up after some good watering. The problem is I have noticed numerous whitish spots on the leaves today. I cannot see an insect. The spots are definitely an ivory or whitish color. Also, there were several buds on the plant which are no longer there. I have grown roses before, and I've looked for aphids, the webbing that spider mites leave, and other things, and have not seen any of these. I have never actually seen white spotting on leaves before. I am rather desperate because my son gave it to me for Mothers Day. Any suggestions at all would be appreciated. Will send a photo if necessary.
Thank you very much
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Answer
Powdery Mildew
Usually sprayed at nurseries to control
Water source near by?
You can control by keeping watering to a min and allow to dry in between.
Also those  varieties are susceptible to this type of disease.
You didn't say what you were feeding them?
High Nitrogen stresses plants out.
Use a good organic ros?fertilizer
You can control organically
Try one of the following
1 cup milk in gallon water
Baking soda at 1 tablespoon gallon water
Liquid coffee will also work since it is acid water
Liquid seaweed works well too