A hardier and wilder relative of the artichoke; the leaf stems are the part that's eaten rather than the flower buds. A treasured Italian traditional dish. Perennial in zones 6-9. Beautiful plants with huge silver leaves cut and lobed from a thick mid-rib, which is the part eaten. For maximum agricultural production, usually grown as an annual.
As plants approach maturity, they are bundled up and even wrapped with cardboard or straw to blanch the stems and make them less bitter. After a month of blanching, the plant is cut and the leaf and spines trimmed off, leaving the thick meaty mid-ribs. These are usually blanched in boiling water then pan-fried, roasted, used in soup, chilled for a salad, etc. It has an artichoke flavor and can be prepared in the same ways. It is possible to manage the plant as a perennial vegetable; the key is to cut the plants late so the roots store enough energy to sprout the next year.
Cardoon can also be managed as a seasonal hedge or border that grows to 5 ft in summer then dies back over winter, and resprouts in spring. The leaves and stems are a great source of carbon for compost. The huge purple thistle flowers are sought-after for cut flowers and drying. Seeds are nutritious for bird and poultry mixes. In Mediterranean climates, the flowers should be cut before they make seed, as the plant can self-sow. Like artichokes these are an edible thistle, so the plants can have spines on the leaves. Sited properly, this can be used to advantage for boundaries, etc. Herbalists use the leaves as a diuretic tea.