It is possible I suppose. If the fence is rotting, it may be that the ground in that area is just too wet for your plants. Although, Louisiana irises are used to a lot of moisture in their native habitat. I would suggest following the care/treatment info in the links. Cut any of the leaves showing spots back to just a couple inches, dispose of the trimmings in the trash and treat the plants with a good fungicide. How deep are the rhizomes planted? Also. how often do you fertilize and water?
