Rose: Black mold

Biology

Black mold primarily affects material used for propagation. The fungus grows on cut surfaces, such as at the contact points between rootstocks and scions and rootstocks and bud shields. This causes graft failures. A gray-white fungus growth is the first symptom of infection. This growth soon turns black as spores are produced. Certain rose varieties are extremely susceptible, such as R. chinensis var. manetti, while others rose varieties are resistant or immune.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Keep all propagating areas and tools clean. Sanitation is very important in disease prevention.
• Use only disease-free plant stock for planting and propagation.
• Resistant or immune cultivars are available for understock. Rosa multiflora ‘Ragged Robin’ is an example of understock that is immune to this disease.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• None recommeded