C. cardunculus. This striking heirloom perennial plant is grown either as an ornamental or for its edible stems and leaf stalks. Cardoon artichoke seeds grow at least 1.2m (4') tall for a stunning Mediterranean look with huge silvery-green, deeply-cut leaves and thistle-like, hard flowers of rich royal purple. The silvery-grey, fleshy stalks of the inner leaves are eaten. Blanch by wrapping newspaper around the plant when it is 120cm (48") tall. Harvest about 3 weeks later. In the fall the new leaf growth can be treated the same way. Thick stems, steamed and seasoned, are an old-world treat. Unopened flower buds make unusual cut flowers.
Matures in 150-210 days. (Open-pollinated seeds)
It takes some work and a lot of patience to grow artichokes from seed, but it’s worth the effort. Commercial culture is limited to warm areas hardiness zone 7 and above. Artichokes require good soil, regular watering and feeding, plus frost protection in winter. Before frost, cut back to 15cm (6″) tall and mulch with soil, straw or leaves to keep the root from freezing. Uncover in April. Offshoots of these plants should be set out in the spring, so that the older plants can be replaced after a few years. Follow along with this handy How to Grow Artichokes from Seeds Guide and grow food.
Cynara cardunculus var. scolymus
We Recommend: Imperial Star (AR103). Harvesting artichokes in the first year of growth is a real benefit for growers. Imperial Star grows beautifully in an open field situation. Productive and yummy!
Season & Zone
Season: Cool season
Exposure: Full sun
Zone: 6-9 (hardy in Zone 5 if you use mulch and cloche cover)
Start indoors in late January to early February under bright lights.
Sow 2 seeds per pot, 5mm (¼”) deep. Keep moist in a warm place until seeds germinate in 10 to 21 days. Transplant seedlings into the garden 2 weeks after the last average frost date for your area. Artichokes need a cool period (250 hours) below 10°C (50°F) to induce flowering, but will not survive hard frost. Space plants 1m (3′) apart. Seeds can also be germinated between damp sheets of paper towel.
Ideal pH: 5.6-6.6. Select a sunny, sheltered location with well-draining soil. Dig in lots of compost or rotted manure and add half to 1 cup of complete organic fertilizer per plant. On the coast, with protective mulch, these plants may overwinter. In late October cut back to 15cm (6″) tall, and mulch well with straw, soil, leaves, or burlap, to keep the roots from freezing. Uncover in April.
In optimum conditions at least 70% of seeds will germinate. Usual seed life: 1 year.