This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
(Cynara Cardunculus, Linn.). A thistlelike plant of southern Europe, cultivated for the thick leaf-stalk and midrib.
It is thought to be of the same species as the artichoke, and to have been developed from it by long cultivation and selection. See Cynara. The plant has been introduced into South America, and has run wild extensively on the pampas. Darwin writes that "no cultivated plant has run wild on so enormous a scale as the cardoon." From the artichoke it differs in taller and more prickly growth and smaller heads. The cardoon is perennial, but it is not hardy, and is treated as an annual. Seeds are sown in spring, either in pots under glass or in the open where the plants are to stand. The later sowing is usually preferred. The plants are given rich soil and should have abundant moisture supply, for they must make continuous and strong growth. When the leaves are nearly full grown, they are tied together near the top, straw is piled around the head, and earth is banked against it. This is to blanch the plant, for it is inedible unless so treated. From two to four weeks is required for the blanching. The procedure is not very unlike that adopted for the blanching of celery or endive. If the plants are late, they may be dug just before frost and blanched in a storage pit. The plants are usually grown 2 to 3 feet apart, in rows which are 4 feet apart.
They are sometimes grown in trenches, after the old way of growing celery. Cardoon is very little known as a vegetable in America except among foreigners. L. H. B.