Bright orange spots, or pustules develop on the upper leaf surface with corresponding bright orange spore masses beneath. Severely infected leaves will drop prematurely. The most common and obvious infections occur in early summer. Moist air is essential for the development and spread of rose rust. The fungus may persist in the plant stems and the spores can over-winter on the soil surface, on fallen plant debris.
Cultural control: Prune out stems showing early spring infections. Product Solution: For use on all ornamental plants spray preventatively or at first sign of infection with Multirose Concentrate 2, Multirose 2 ready To Use, Fungus Fighter Disease Control or Systhane Fungus Fighter.