CARDOON, Cynara cardunculus (natural order Compositae), a perennial plant from the south of Europe and Barbary, a near relation of the artichoke. The edible part, called the chard, is composed of the blanched and crisp stalks of the inner leaves. Cardoons are found to prosper on light deep soils. The seed is sown annually about the middle of May, in shallow trenches, like those for celery, and the plants are thinned out to 10 or 12 in. from each other in the lines. In Scotland it is preferable to sow the seed singly in small plots, placing them in a mild temperature, and transplanting them into the trenches after they have attained a height of 8 or 10 in. Water must be copiously supplied in dry weather, both to prevent the formation of flower-stalks and to increase the succulence of the leaves. In autumn the leaf-stalks are applied close to each other, and wrapped round with bands of hay or straw, only the points being left free. Earth is then drawn up around them to the height of 15 or 18 in. Sometimes cardoons are blanched by a more thorough earthing up, in the manner of celery, but in this case the operation must be carried on from the end of summer. During severe frost the tops of the leaves should be defended with straw or litter. Besides the common and Spanish cardoons, there are the prickly-leaved Tours cardoon, the red-stemmed cardoon and the Paris cardoon, all of superior quality, the Paris being the largest and most tender. The common artichoke is also used for the production of chard.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)