My knock roses have been thriving well for several years until recently. I pruned both in the fall and this spring In the fall because they were intruding on my walkway and sticking those whole had to use it. When the early rains were plentiful they bloomed well. now they are filled with rust blight and fungus and branches are dying with much falling foliage. They seemed to have been grown from grafts. I have begun to water them and they have livened somewhat. I have been reluctant to apply a fungicide. What do you suggest? if they die, what should I plant. I am aware it is not advisable to plant roses in that location. I would want some kind of perennial that is deer resistant. What are your thoughts and recommendations?