Arctium is a genus of biennial plants commonly known as burdock, family Asteraceae. Native to the Old World, several species have been widely introduced worldwide. (Sourced from Wikipedia).
Burdock is a strong growing biennial and the fairly bitter but tender young foliage of the spring regrowth is eaten as a green vegetable. The taproots are used as a vegetable as well, and the flavour is between that of a parsnip and Jerusalem artichoke.
Burdock requires a moist humus rich soil and full sun, although it will tolerate some shade. It is also fully cold hardy and dies down in winter. Propagate from seed in spring or late autumn (fall). Thin seedling to 15cm apart, and to ensure high quality, long straight roots, dig the soil to a depth of 60cm and incorporate compost before sowing.
Keep the soil moist and weed the crop regularly, particularly when the plants are young. Remove the flowers and burrs to promote root growth. For cooking collect young shoots and leaves in spring. Lift the roots in autumn when they are at least 30cm long.
For cooking, scrape the young leaf stalks and cook them as you would celery. Use the roots raw as a salad vegetable or cook for stir fries as you would carrots.
information sourced from The Complete Book of Herbs