Answer: It sounds like your rose has "black spot." A fungus causes black spot on roses. Some cultural practices may be helpful in controlling it. These include planting varieties resistant to it, ensuring your plants are in a location with good air circulation, avoiding wetting the leaves when watering, and cleaning up, removing and destroying any infected leaves. Do this especially well each fall to minimize reinfection from year to year. A clean layer of organic mulch (such as shredded bark or half finished compost or chopped leaves) applied before the plants leaf out again in spring should also help prevent reinfection. Or, there are fungicides you can spray on your roses to control black spot. You will find a huge variety of products in your local garden center. Be sure to apply according to label directions.
Good luck with your roses.
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