Yellow and Black Spots on Roses

Black spot is the bane of many rose gardeners. Black spots, yellowing, and leaf drop are the telltale symptoms of this fungal disease. Black spot, as common as it is, is not hard to combat if you have a few basic skills and perseverance.

Origins

• Black spot is a soil-borne fungus that splashes onto leaves with rain and irrigation. Roses that are overgrown, crowded, or over watered are susceptible to infection. The fungus can be spread from soil to plant, leaf to leaf, and plant to plant.

Prevention

• Air circulation and cleanliness are important to prevent black spot. Give roses plenty of room to grow and trim back crowded canes and spent blooms. Always rake up fallen leaves and petals as they fall to prevent the spread of the fungus.

Chemical Control

• Bad black spot infestations will require spraying. Choose a fungicide labeled for black spot and use according to label instructions. Spray the tops and bottoms of both leaves and petals, as well as the canes. Spraying the soil beneath the bush kills fungal spores in the soil.

Plant Selection

• Choose roses known for disease resistance. Among the varieties resistant to black spot are Knock Out, Robin Hood, Lavender Lace and George Burns. Rosa alba and rugosa varieties are excellent old-fashioned roses that are resistant to fungus.