This vegetable is a member of the thistle family and is a close relative of the globe artichoke, although it looks more like celery. Cardoon is cultivated for its fleshy root and stems, some of which are six or seven feet long. There are also many wild varieties, but they are smaller and less tender. Tenderness in the cultivated varieties is ensured through blanching, which involves tying the leaves together after they have attained maximum growth and storing them for some time before marketing.
The artichoke enjoyed by the ancient Greeks and Romans was actually cardoon. It also figured prominently in medieval cooking. It is popular in Europe today, but less so in the United States, where the stems are often known as chard. They should not be confused with real chard, or spinach beet.
The main root, which is thick, fleshy and tender, is often boiled, then served cold in salad. It may also be sauted in butter or served in Bechamel sauce. The stems may be treated like asparagus or celery, and the leaves, like spinach.
Provide a deep, rich soil. Manure may be added to the bottom of the planting trench. Cardoon is planted in late May. Planting in trenches can be done on light soil but only on the surface in heavy soil. If trenches are used they should be 2 feet wide and 1 1/2 feet deep. Space the rows or trenches 4 feet apart. On the surface, plant in hills 4 feet apart with 4 to 5 seed per hill. Thin to the strongest seedling. The leaf stalks become pithy if the soil gets too dry. Blanching requires 1 to 2 months. Tie the leaves into an upright position then either fill in the trench, mound the plants with soil, or wrap the plants with heavy paper.
Harvest when blanching is finished.
Cardoon may be stored in a pit until early winter.