Cardoon is a tender perennial vegetable grown as an annual. Sow or transplant cardoon into the garden 3 to 4 weeks after the average last frost date in spring. Start cardoon from seed indoors 6 weeks before transplanting it into the garden. Cardoon, which is grown for its young leaf-stalks, will be ready for harvest 120 to 150 days after planting.
Description. Cardoon looks like a cross between burdock and celery. It is grown for its young leaf-stalks which are blanched and eaten like celery. Cardoon has heavy, gray-green, fuzzy leaves that are deeply cut leaves and a heavy, bristled flower head. Cardoon is a member of the artichoke family and can grow up to 4 feet (1.2m) tall and 2 feet (.6m) wide.
Yield. Plant 1 or 2 cardoons for each household member.
Site. Grow cardoon in full sun; cardoon will tolerate partial shade. Plant cardoon in well-drained soil rich in organic matter. Prepare beds in advance with aged compost. Cardoon prefers a soil pH of 6.0 to 7.0.
Planting time. Cardoon is a tender perennial vegetable grown as an annual. It is best grown from transplants set in the garden 3 to 4 weeks after the average last frost date in spring. Start cardoon from seed indoors 6 weeks before transplanting. It germinates best at 75°F (24°C). Cardoon will be ready for harvest about 120 days after planting.
Planting and spacing. Sow cardoon seed ¼ inch deep. Thin cardoon from 18 to 24 inches (45-61cm) apart. Space rows 36 to 48 inches (76-122cm) apart.
Companion plants. Perennial vegetables such as asparagus; not root vegetables or vines.
Container growing. Cardoons do not grow well in containers. Chose a 5-gallon (19 liter) container to grow one cardoon.
Caring for Cardoon
Water and feeding. Evenly water cardoon but allow plants to dry out between watering.
Add aged compost to planting beds before planting and again at midseason.
Care. Cardoon is commonly blanched to improve the flavor and to make it more tender. About 3 to 4 weeks before harvest, when the plant is 3 feet (.9m) tall, tie the leaves together in a bunch and wrap paper or burlap around the stems to about 18 inches 45cm) high, or hill up soil around the stems.
Pests. Aphids can attack cardoon. Pinch out infested foliage or spay aphids off plants with a blast of water.
Diseases. Cardoon has no serious disease problems.
Harvesting and Storing Cardoon
Harvest. Cardoon will be ready for harvest 4 to 6 weeks after blanching. Cut stalks off at ground level and trim away the leaves.
Storing and preserving. Cardoon stalks will keep in the refrigerator for 1 to 2 weeks. Wrap them in paper or plastic. Cardoon can be frozen, canned, or dried; handle it like celery.
Cardoon Varieties to Grow
Varieties. ‘Large Smooth’; ‘Large Smooth Spanish’; ‘Ivory White Smooth’. Grow any variety available in your area.
Common name. Cardoon
Botanical name. Cynara cardunculus