Answer: Unfortunately, based on your description I am not certain which plant you have but the powdery white spots may be powdery mildew. This usually happens when weather conditions are conducive to it and where air circulation is poor. You may be able to rinse it off with water from the garden hose. Or, you might want to consult with your local county extension. Based on knowing which plant it is and a more definite identification of the spots, they should be able to make a more specific control recommendation.
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