My customer has the common black spot and rusting leaves on some of her rose bushes. She likes to do organic options when possible. Her main concern is that she doesn't want to do anything that harms the bees that visit her garden. I've been looking online and there seems to be lots of information and options for how to treat black spot and rose rust. Some say you have to do a series of preventative sprays nearly year round. Others say you can treat as needed. Please, what has been your experience with this and can you recommend a good treatment option?