Fennel

Fennel is a Mediterranean herb and vegetable in the carrot family, prized for its feathery foliage, yellow umbel flowers, and distinctive anise-like aroma. Both the herb form (grown for leaves and seeds) and the bulbing form (Florence fennel, grown for the swollen leaf base) are cultivated. In Nordic gardens it behaves as a biennial or annual and requires winter protection or fresh sowing each year. It demands a warm, sunny position with well-drained soil and dislikes root disturbance.

Growing

Start seeds indoors 5–6 weeks before transplanting, sowing 1–2 cm deep once soil indoors stays above 10 °C. Use deep individual cells or root trainers to minimise root disturbance — damaged roots trigger premature bolting. Germination takes 10–20 days. Transplant outdoors once nights stay reliably above 10 °C, spacing plants 15–20 cm apart in rows 40–50 cm apart. Alternatively direct-sow into warm soil (at least 10 °C) at the same depth. Handle transplants very carefully; disturb the root ball as little as possible.

Care

Fennel needs consistent moisture, especially during bulb formation, but will not tolerate waterlogged soil. Water deeply and evenly; mulch around the base to retain moisture and regulate soil temperature. Do not feed heavily — excessive nitrogen promotes lush foliage at the expense of bulb development. Keep fennel isolated from most other vegetables, particularly other Apiaceae and brassicas, as it is allelopathic and inhibits neighbouring plants. Earth up bulb fennel by drawing soil around the developing bulb to blanch it and improve flavour. If frost threatens before harvest, mulch generously with straw or leaves to extend the harvest window.

Harvest

Harvest bulb fennel when the base has swollen to a firm, compact globe, typically 7–10 cm across. Cut the bulb at soil level with a sharp knife. Herb fennel leaves can be snipped continuously once plants are established; harvest fronds before flowering for the best flavour. Harvest seeds when the umbels turn light brown but before they shatter — cut whole stems and dry upside-down over paper. Do not wait for full yellowing or seeds will be lost.

In the kitchen

Use fresh fennel fronds like dill — chop into sauces, dressings, cream cheese, and fish dishes. Slice raw bulb thinly for salads or shave over citrus. Roast or braise bulb halves until caramelised. Add fennel seeds to bread, biscuits, sausages, and soups for deep anise warmth. Fennel stalks can be eaten like asparagus when young and tender.

Storing

Store harvested bulbs unwashed in the refrigerator crisper for up to 2 weeks. Fronds are best used fresh but can be wrapped in damp paper and refrigerated for 3–5 days, or frozen (blanched) for up to 3 months. Dry seeds fully before storing in an airtight container in a cool, dark place; seeds remain potent for 1–2 years. Sliced fennel can be pickled in brine or vinegar and stored in sterilised jars for several months.