Last season my climbing rose had a very strong fungal infection, black-spot or something similar. It affected most of the leafs. This spring I have noticed black rings on most of the canes (see pictures). The canes with the rings have none to almost none new growth. Only one cane looks free of these spots and seems to have new growth.
My questions are:
- Does it look to you like these canes are affected by a fungal infection or are those marks cold damage or something else?
- Should I trim down all those canes with marks?