#1 This year, on one of my rose bushes, the flowers are small with several branched out stems/blooms. Does this have anything to do with how I cut it back in the fall? I live in Michigan. #2 What is the cause of the rose leaves looking like this? Is it an insect or a disease?
I am not sure what your roses foliage looks like as I have no photos to take a look at. From your question #1 I wonder if the desired rose has died or is extremely weak and the hardy root stock below ground has sent up some of its own shoots/canes. The smaller flowers can signal this. From your question #2 I am hoping that your roses do not have rose rosette disease which can really mess up the foliage. Sometimes an herbicide sprayed nearby drifts over onto the roses causing the foliage to be deformed as well. Again, without photos to see the problems it is tough to know for sure.