Cardoon is considered to be a tender perennial. In cold climates, it is often grown as an annual. It is a member of the artichoke family with thick, deeply cut, thistle-like leaves and a violet-colored thistle flower head in late summer.
Commonly it is called Artichoke Thistle. The Cardoon Artichoke Thistle plant is grown both for eating and for its importance as a medicinal herb, and it easily grows from Cardoon seeds.
The cardoon has become important as a medicinal herb in recent years following the discovery of cynarin. This bitter-tasting compound, which is found in the leaves, improves liver and gallbladder function, stimulates the secretion of digestive juices, especially bile, and lowers blood cholesterol levels.
The leaves are anticholesterolemic, antirheumatic, cholagogue, digestive, diuretic, hypoglycemia, and lithontriptic. They are used internally in the treatment of chronic liver and gallbladder diseases, jaundice, hepatitis, arteriosclerosis, and the early stages of late-onset diabetes. The leaves are best harvested just before the plant flowers and can be used fresh or dried.
Start Cardoon seeds indoors 4 - 6 weeks before the last frost. Cardoon herb seeds can be started in small peat pots with seed starting mix. Transplant outdoors into the herb garden after the danger of frost has passed. The Cardoon plant prefers full sun and soil rich in organic matter. Prepare a bed in advance with aged compost. It does not grow well in containers.
USDA Zones: 6 - 9
Height: 60 inches
Bloom Season: Late summer to mid-fall
Bloom Color: Violet blue
Environment: Full sun
Soil Type: Moist, well-drained sandy to clay soils