This year I have held off on spraying anything. Last year I just used a cheap dollar store brand dish detergent and it seemed to help control the rust on those plants. I have no proof it was the detergent or coincidence, but I think at least some form of Dawn dish detergent has been actually shown to aid in controlling rust, but I know of no special ingredient in it that was the reason. I think you see Dawn detergent recommend all the time just because it was the one actually used in the test, I doubt it is actually much better than many others. Although, I have read to avoid some, I just don't remember why that was.
