Answer: Sounds like your rose bush has powdery mildew. You can help your roses avoid the disease by making sure the rose bushes get plenty of sunshine and has enough space all around for good air circulation. There are a few fungicides on the market that you can use to stop powdery mildew. The safest is one called 'Rose Defence'. It'sa neem oil based product, biodegradable and is safe for insects, animals and humans.
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