Answer: If there's a powdery white coating on the leaves, it indicates a fungal disease called powdery mildew. This disease is common on roses that do not get adequate sunlight and there is too much humidity and poor air circulation around them. If the leaves themselves are white - meaning no color where they should be green, the cause can be a virus, or lack of nutients. Try feeding your roses and see if that does the trick. If new growth does not come in properly, suspect a virus. You can pinch off the affected leaves and your roses will still bloom, but the virus will remain in the plant until the plant dies. Best wishes with your miniature roses!
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