Typical winter vegetable and from time immemorial often cultivated as an alternative for asparagus. A fine vegetable with long, truncated roots with a deep black skin. Duplex is known for its resistance to running to seed. Do not sow the long seeds too deep in the soil. Requires a light, deeply loosened up soil (little fertiliser) and is easy to grow. The roots can overwinter in the ground. Peel well before cooking. After peeling leave the roots in a mixture of water and milk to stop discolouration. Delicious in raw vegetable salads and stewed.