Black Spot (Rose)
fungusDiplocarpon rosae
Common fungal disease of roses causing black spots on leaves. Included because many gardeners grow roses alongside food crops.
Identification
Circular black spots with feathery margins on upper leaf surfaces. Yellowing around spots. Leaves drop prematurely.
Damage & Symptoms
Defoliation. Weakened plants. Reduced flowering. Plants become susceptible to other stresses.
Organic Control
Neem oil. Baking soda spray (1 tbsp per gallon with soap). Remove fallen leaves. Copper fungicide.
Chemical Control
Myclobutanil. Chlorothalonil. Triforine.
Prevention
Resistant varieties. Water at base. Morning watering. Good air circulation. Remove fallen leaves. Prune for air flow.
Data confidence: medium | Source: curated_ipm