I have rose canker quite often, and most of time it's a lost cause.
It would start somewhere, then I would cut back until the new tissue, green and white core. But then it would start spreading again. Either in a different cane or very same cane.
I do practice safety, such as sanitize my pruner with alcohol. Dispose the black cane in trash cane. Yeah, all the advice flying around I have tried them all. And I am not able to save all my rose. I even use the copper type chemical to kill the fungus, but that doesn't work quite well for all. I would keep cutting until nothing left to be cut :(
Is there anyways I could do to save my rose?
Please keep in mind I'm in hot and humid condition.