Chelle - can't help you 'cuz I have no humidity. I have 3 (count them, 3) roses that have a little bit of blackspot, and that's it. 1 BlueGirl, 1 Sterling Silver, & my Austrian Copper (BS magnet). I always feed my roses Age Old when they start looking uberdroopy, but usually my droopiness has to do with lack of water & 100+ deg heat. I do like that Grootendorst, very pretty! Sounds like if you offered iron that might help with weak stems? I know that iron encourages green growth...
