Normal green pods containing succulent green beans when picked young, beans change to a violet-purple colour if left to mature and harvested as a dried bean.
Sow February under cloches, or March-April outdoors. Ideally sown in double rows, 5cm (2in) deep and 20-23cm (8-9in) apart in the row, with 20-23cm (8-9in) between each row. Allow at least 60cm (24in) between each double row. Germination takes about 10 days.
Keep well watered particularly when flowers are setting. Pick regularly once pods are full to promote further pod production.