Cardoon

About Cardoon

Cardoon is a tall, thistle-like cousin of the globe artichoke grown for its thick leaf stalks, which are tied up and blanched in fall and then cooked. Its silvery leaves and purple flowers also make it a striking ornamental. In California the wild form (artichoke thistle) is an invasive weed: it is on the state noxious weed list and Cal-IPC rates it Moderate, so cut flower heads before they set seed.

Perennial where winters are mild (NC State lists zones 7-10); elsewhere grow it as an annual from transplants. It is touchy about frost and turns bitter in hot weather, doing best with cool summers.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Days count from planting. Oregon State starts seed in a greenhouse in early to mid-March and sets plants out in mid-May (or direct-seeds in May) for an October to November harvest; Illinois gardeners start seed indoors in late January or early February. Plant in a shallow trench and fill it in as plants grow.

Soil

Deep, fertile, well-drained soil with room for the large taproot; water evenly, since drought makes stalks pithy.

Work plenty of manure or compost into deep, fertile soil before planting, and follow a soil test for phosphorus and potassium.

Feeding

• early spring, before flower buds form: nitrogen fertilizer. Oregon State applies the nitrogen all at once at this stage; spread it around the plants and water it in.

Don't let plants go short of water: drought makes the stalks pithy, and hot weather makes them bitter.

Harvest

Near maturity, tie the leaves together and wrap the plant in burlap or paper for 4 to 5 weeks to blanch it. Then cut just below the crown and trim to the pale heart of stalks.

Each plant is blanched and cut once, in fall. Where it is perennial (about zone 7 and warmer) it regrows from its taproot for another fall harvest; where it is grown as an annual, it is a single harvest.

Varieties (6)

Oregon State names 6 cardoon varieties, with few details; it advises choosing spineless types over spiny ones.

Pests to watch for

Brown garden snail, Slugs, Aphids

Diseases and problems

Root and crown rot, Gray mold (Botrytis), Powdery mildew

In the kitchen

The blanched inner leaf stalks are trimmed and cooked as a vegetable, prized in Mediterranean cooking. The roots can be cooked too, and the flower heads can be eaten like small, less meaty artichokes.

Keeping it: Cardoon is best used fresh; kept at about 32F with high humidity, it holds 2 to 3 weeks.

Safety: Many types have sharp spines on the stems and leaves, so wear gloves when tying, blanching and trimming (NC State).

Pets: Not listed by the ASPCA