Can I transplant ground cover rose bush in September?
Yes you can. Be sure to water it with some water that has a good root stimulator and a product called Super Thrive mixed in the same water. This will help the rosebush get its roots going well and deal with the transplant shock as well. I would prune it back a bit prior to transplanting and remove at least 80% of the buds and blooms if not all. This will help it focus its energy on getting its roots set instead of trying to bloom well and get its roots established. I water them with such a mix at least 4 times as it needs watering after transplanting.