Overview of Cardoon
Cardoon (Cynara cardunculus) is a close relative of artichoke (Cynara cardunculus ssp. cardunculus). It makes a great dramatic statement in gardens, with its large, spiny, silvery foliage and large, thistle-like flowers.
Cardoon is an ornamental edible, as the blanched stems can be eaten, although doing so would ruin the ornamental appeal of the plant. Cardoon has an an artichoke-like flavor, and it was popular in ancient Greek, Roman, and Persian cuisine, and through the medieval and early modern periods in Europe, as well as in colonial America. Cardoon is still cultivated for food in southern Europe and northwestern Africa.
This fast-growing, tender herbaceous perennial in the aster family (Asteraceae) is native to the western and central Mediterranean where it was domesticated in ancient times. It is hardy only in zones 7a to 10b, so is treated as an annual in cold climates. In some mild climates, including Argentina, Chile, Australia and California, it has become naturalized and is considered a weed.
In their first year, plants produce an enormous urn-shaped rosette. The leaves emerge silver (from their covering of tiny hairs) and eventually become grey-green as they grow up to 3 feet long. The alternate basal leaves have deeply cut, jagged margins with heavy yellow spines along the edges, especially along the petioles. Some spineless varieties are available.
New leaves continue to emerge from the center of the plant throughout the season. Older leaves tend to lie down on the ground, where they can become matted and smother adjacent plants. Plants that successfully survive the winter produce a number of smaller and denser rosettes.
Plants generally don’t bloom in colder climates, as the growing season is usually not long enough for this to happen. The large, thistle-like inflorescences are quite ornamental. The violet-purple flowers are produced in a heavily spined capitulum (head) about 2 inches in diameter.
Several of the globose inflorescences are produced on each plant. Bees and other pollinators visit the flowers. Under the right conditions, plants may self-seed. In mild climates, this species may become invasive, but this is not a concern in cold winter areas.
Landscape Use of Cardoon
Cardoon offers great textural contrast and can add a Mediterranean look in landscapes. With its somewhat upright form (at least of the new growth) and bold, deeply lobed leaves it is quite different from the mounded habit and medium or fine-textured leaves of many garden plants. Plant cardoon amid low growing companions as a focal point. Combine it with upright grasses such as feather reed grass (Calamagrostis x acutifolia ‘Karl Foerster’) or switchgrass (Panicum virgatum) or surround it with a mass of interspecific hybrid zinnia.
Choose companion plants that contrast with the blue to silver color of the foliage, or for a color echo, plant dusty miller (Senecio cineraria), lambs ears (Stachys byzantina). Other companions include annuals with blue, purple, rose, or burgundy flowers. Plants with red or bronze foliage make an even more dramatic contrast. Possibilities include Euphorbia dulcis ‘Chameleon’, purple leaf sweet potato vine varieties (Ipomoea batatas ‘Blackie’ and others), and coleus.
Cardoon can be grown as a container plant, but it requires a very large container.
This plant grows best in full sun in well-drained soil in a site protected from strong winds. It also needs plenty of room to spread and may not be appropriate for small spaces.
Gardeners in colder climates may have success overwintering cardoon by cutting plants back to about a foot tall, covering with soil or compost, covering that with a bushel basket or rose cone, and then draping the entire thing with a tarp to shed rain. Remove the covering in spring after the snow melts and see if the plant survives. If so, it should bloom that year.
Propagating Cardoon
Cardoon can be started from seed sown indoors 6 to 8 weeks before the last frost. Transplant to the garden after the danger of frost is past. Under ideal conditions, plants can grow 3 to 4 feet tall and 4 to 5 feet wide by the end of the growing season, so allow them sufficient space. To maintain a more vase-shaped plant, trim off the older leaves as they flop, either cutting or just snapping them off. When grown as an annual, cardoon has few pests (although in the eastern U.S. there are reports of it being attacked by Japanese beetle) and is not favored by deer.
Varieties of Cardoon
Named cardoon varieties are more common in European seed catalogs than in American seed catalogs. Stems are often blanched for a few weeks before harvest by tying plants up and excluding sunlight with a cloth, paper, or cardboard covering. A few varieties include:
- ‘Bianco Avorio’ has thin stalks and matures 110 days from transplant.
- ‘Gobbo di Nizza’ (“hunchback of Nice” in Italian) features thick stalks with few spines. Matures 110 days from transplant.
- ‘Porto Spineless’ is a spineless variety with a compact habit, growing 3 to 4 feet tall. Matures 100 days from transplant.
- ‘Rouge d’Alger’ is thornless, with stalks with pinkish bases and pale green leaves.
- ‘Spineless White’ is an old variety with wide, thornless stalks with good eating quality. Introduced before 1750.
Author: Susan Mahr, University of Wisconsin—Madison
Reviewers: Allen R. Pyle, Horticulture Outreach Specialist, Bruce Spangenberg, Horticulture Outreach Specialist, UW—Madison Extension
Revised: July 2026
