Most rose breeders get black spot. I get some because we get a fair bit of misty weather being on the edge of the tableland country. I use only natural sprays. I keep the fertiliser up to them. i put slow realease after they get their new leaves on and then I give them a good water with sea weed fertiliser every two to three weeks. I lightly prune them mid summer which extends their flowering well into autumn. I nearly always water them after dark. I'll post a few more pics soon.