Answer: Some roses are just more prone to diseases than others regardless of what you do so if you decide to replace your roses be sure to choose those that are resistant to diseases. Roses need at least 8 hours of sun each day and they need to be pruned on an annual basis to remove old and diseased growth and to open them up to better air circulation. In southern California that means pruning your roses back in December or January. Cut all the canes back to 18-24 inches from the ground, remove the most diseased looking canes and save the best 3-5 canes. New growth will develop on these canes. Best wishes with your roses.
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