Symptoms are light-colored spots on rose petals; these spots quickly turn to brown blotches. Infected buds fail to open, and discoloration may extend down the stem. Development of a slimy, gray-brown mold follows, concluding with rotting buds.
Canes may develop dark brown, sunken cankers. This disease can occur throughout the year, but often develops on blooming plants during cool weather with high humidity levels. Planting conditions that allow air circulation help discourage this disease