More Garden Diseases: Bacterial Leaf Spot, Late Blight, Rust, and Anthracnose

Additional diseases challenge organic gardeners. Early identification and cultural controls minimize damage.

Bacterial Leaf Spot

Small black/brown water-soaked spots on leaves, progressing to holes and leaf drop. Common on tomatoes, peppers, cabbage family. Worsens in wet weather. Control: immediately remove infected leaves.

Late Blight

Wet gray/green leaf spots → white fungal growth on undersides. Affects tomatoes, potatoes late season. Choose resistant varieties regardless of cost. Remove infected parts. Prevention: morning watering allows daytime drying, discouraging fungus.

Common Rust

Reddish-brown powdery spots on leaves (rub off when touched). Affects asparagus, beans, corn, onions. Control: hand-pick infected leaves; destroy severely affected plants. Prevention: proper spacing for air circulation, regular weeding and pruning.

Anthracnose

Prevalent in warm, wet US climates. Small spots → pink spores in centers. Affects cucumbers, tomatoes, melons, beans. Prevention: lime juice spray on leaf buds. Remove and destroy severely infected plants.

Cultural practices—spacing, pruning, watering timing, resistant varieties—form the backbone of organic disease management.