How to grow cardoon
Overview
Cardoon (Cynara cardunculus) is a thistle-like perennial grown for its blanched leaf stalks, which have a flavour reminiscent of artichoke. It is a productive vegetable for Australian gardens, thriving in full sun and well-drained soil. Growers must blanch the stems for 2-3 weeks before harvest to ensure tenderness.
Varieties
- Gigante di Romagna — A vigorous Italian variety with large, thick stems that blanch beautifully.
- Plein Blanc Inerme — A spineless variety that is easier to harvest and prepare.
Soil Preparation
Cardoon prefers deep, fertile, well-drained soil with a pH between 6.0 and 7.5. Incorporate plenty of aged compost or well-rotted manure before planting. Good drainage is essential to prevent root rot.
Growing Guide
Sow cardoon seeds 1-2 cm deep in rich, well-drained soil in full sun. Space plants 60-90 cm apart with rows 1 m apart. Keep soil moist during germination but water sparingly once established. To produce tender stems, blanch them by wrapping with paper or tying leaves together for 2-3 weeks before harvesting. Remove lower leaves as the plant grows to focus energy on stem development.
Sowing
Sow cardoon seeds directly in the garden at a depth of 1-2 cm, spacing seeds 30 cm apart. Germination takes 10-14 days. Alternatively, start seeds in punnets and transplant when seedlings are 10-15 cm tall. Thin to the strongest plant per spot.
Care
Feed cardoon with a balanced fertiliser at planting and again mid-season. Remove lower leaves gradually as the stems develop. Blanch stems by wrapping them with paper or tying leaves together for 2-3 weeks before harvest to improve tenderness and flavour.
Companion Planting
Cardoon grows well with legumes like beans and peas, which fix nitrogen, and with aromatic herbs such as dill and tarragon. Avoid planting near fennel or potatoes, as they may compete for nutrients or attract similar pests.
Common Pests & Risks
Aphids and snails are common pests. Control aphids with a strong water spray or insecticidal soap. Hand pick snails and slugs or use organic baits. Powdery mildew can occur in humid conditions; improve air circulation and avoid overhead watering.
Harvesting
Harvest cardoon stems when they reach 30-40 cm in length and are thick and fleshy. After blanching, cut the stalks at the base using a sharp knife. Use immediately or refrigerate for up to a week.
In the Kitchen
The blanched stems are used raw in salads or cooked in braises, grills, and soups. They have a mild, artichoke-like flavour. Store harvested stems in the refrigerator for up to a week. Only blanched stems are edible; leaves are bitter.
Troubleshooting
Yellow leaves: nitrogen deficiency, apply balanced fertiliser. Poor stem development: insufficient water or nutrients, ensure consistent moisture and side-dress with compost. Bolting: caused by stress or heat, plant in cooler season. Black spots: fungal disease, avoid overhead watering and improve air circulation. Stunted growth: root rot due to poor drainage, grow in raised beds.