Cardoon

In autumn, before the first frost, tie the long leaves loosely together and cover the soil around the plant with leaves, straw or brushwood; in hard frost add horticultural fleece as well, but keep it airy so that nothing rots. Choose a wind-sheltered, sunny position with well-draining soil, because winter wet is more dangerous than the cold, and take the protection off in spring only when strong night frosts no longer threaten.

Cardoon can be propagated in three ways. Sowing is the most common method. Start the seedlings from February to March on a windowsill or in a greenhouse at about 20 to 22 degrees. Lay the seeds about 1 to 2 cm deep in moist seed compost. Soaking in lukewarm water for 24 hours speeds up germination. Germination usually takes 10 to 14 days. After germinating, the seedlings are fine at 15 to 18 degrees in a bright spot, but not in full sun. Once the young plants have five true leaves and are about 30 cm tall, harden them off slowly and plant them out after the Ice Saints in mid-May with generous spacing of at least 100 by 75 cm. Division is for perennial stands. In early spring, when the plant starts into growth again, you can divide established clumps every 4 to 5 years. Note that cardoon forms a strong taproot. Dig up the mother plant generously and deeply, separate strong basal shoots with a sharp, clean knife and make sure each piece gets enough root. Trim the foliage back a little to reduce evaporation. Plant the new plants straight away in their new position and keep them well watered until they have rooted. Daughter rosettes or side shoots as offsets. Mature cardoons form basal side rosettes at the foot of the mother plant. In spring, separate these with a little root, without having to dig up the whole clump, and plant them directly in their final position. This is the quickest way if a vigorous mother plant is already there. All three methods suit the home garden in Germany, Austria and Switzerland. Cardoon is frost-tender. Plant it outdoors only after the last night frosts, that is, the Ice Saints around mid-May.