Black Spot of Rose—Diplocarpon rosae
Black spot is caused by a fungus that overwinters on living or dead plant tissue that was infected in the previous growing season. The fungus attacks the leaves, causing yellowing and defoliation, and sometimes attacks the flowers and stems. Defoliation causes the plants look bare and straggly and gives them less energy to produce flowers.
Click on images to view full-size
Identification and Control Information
- Report on Plant Disease: Black Spot of Rose (PDF)—University of Illinois Extension
- Fact Sheet with Symptoms, Management Options and Resistent Varieties (PDF)—The Ohio State University Extension
[Photos, left to right: Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org; Yuan-Min Shen, Taichung District Agricultural Research and Extension Station, Bugwood.org; Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org]