Rose diseases cause unsightly leaves and poor flowering and can result in the death of the plant. In areas with high humidity where diseases are most severe, disease-resistant cultivars offer an alternative to constant treatment with fungicides.
Black Spot Disease
Black spot is the primary disease that affects climbing roses in many parts of the country, especially where humidity is high. Infected leaves develop spots and eventually turn yellow and drop off.
Climbing rose cultivars that are resistant to black spot disease include Eden, Lady Banks, John Davis, New Dawn, Pinkie, Prosperity, Rambling Red, Red Climber and William Baffin. Dortmund, Dublin Bay and Royal Sunset are resistant to powdery mildew and rust diseases as well as black spot.
Disease-resistant cultivars are not disease-proof. When disease pressures are high enough, climbing roses may develop diseases, but resistant varieties are more likely to survive than varieties that are not resistant. In addition, diseases can change over time, allowing them to infest resistant varieties.