Pests & diseases › Chocolate Spot
Chocolate Spot
Fungal disease of broad beans. Chocolate-brown spots and streaks on leaves, stems and pods.
Symptoms
- Round chocolate-brown spots on leaves
- Brown streaks running up stems
- Spots merging into large dead patches in wet years
- Pods marked with brown blotches
Lifecycle
Worst in cool wet springs on overwintered broad beans. Spores carry on the wind.
What to do
- Remove and bin worst-affected leaves
- Improve airflow — thin out crowded stems
- Foliar feed with seaweed to boost the plant's defences
If it's bad
- No fungicide approved for home use on broad beans
Stop it coming back
- Wide spacing — at least 23cm between plants
- Don't over-feed with nitrogen — weak soft growth is most susceptible
- Mulch with potash-rich material
- Three-year rotation
Crops it goes for
Plan the plot, track every sowing, cook the harvest
Sowing reminders and harvest forecasts for your own frost dates, the Seed Tin, Scan Centre for any label or packet, and the Potty Mouth Garden Club. Free to start.