Fennel the herb is a tall, hardy perennial of the carrot family grown for its feathery, aniseed-scented fronds, stalks and pollen. Wild fennel is essential to Sicilian pasta con le sarde and Provençal fish.
What it is¶
Fennel is a tall, hardy perennial with hollow, blue-green stems and leaves divided into fine, thread-like segments, topped in summer by flat umbels of small yellow flowers. It can reach 1.5–2 m. Every part tastes of sweet aniseed: the feathery leaves (usually called fronds), the young stalks, the flowers and their pollen, and the seeds. The seeds are a spice in their own right and have their own page, fennel seed; this page covers the plant as a herb.
There are three main kinds in the kitchen:
- Herb fennel (Foeniculum vulgare), the ordinary garden perennial grown for leaves and seed. Bronze fennel ('Purpureum' and similar) has smoky purple-brown foliage and the same flavour.
- Wild fennel, the same species growing untended on Mediterranean hillsides and roadsides. Much of it, especially in southern Italy, is the sharper, more bitter piperitum type; Italians call it finocchietto selvatico. It is also naturalised on British sea cliffs and waste ground.
- Florence fennel (var. azoricum), bred for the swollen leaf bases sold as a "bulb". It is a vegetable first, but its fronds are perfectly good as a herb — the most common source of fresh fennel leaf in shops.
Fennel is closely related to dill, which it resembles, and both belong to the same family as parsley, chervil and sweet cicely.
Origins and history¶
Fennel was well known in the ancient Mediterranean. The Greek word for it was marathon, and the plain where the battle of Marathon was fought in 490 BC is traditionally said to have been named for the fennel that grew there. (The hollow stalk in which Prometheus carried fire was narthex, giant fennel, a different plant, Ferula communis.) The Romans ate the shoots and leaves and used the seed, and spread the plant through their empire.
By the early Middle Ages it was established in northern Europe: Charlemagne's Capitulare de villis (around 800) lists foeniculum among the plants for royal estates, and fennel appears in the Old English "Nine Herbs Charm". Medieval cooks paired it with fish, especially on fast days. See physic-and-monastery-gardens.
Fennel now grows wild over large parts of California and Australia, where it is an invasive weed. Fennel pollen as a commercial product is recent: Tuscan and Sicilian cooks have long rubbed dried fennel flowers into pork, but the sieved pollen became a fashionable restaurant ingredient only from the 1990s.
Flavour and aroma¶
The dominant compound is anethole, the same molecule that sweetens aniseed and star anise, so fennel tastes sweet even though it contains little sugar. Alongside it is fenchone, which is camphor-like and bitter; the balance between the two separates sweet cultivated fennel from the sharper wild kind, which has more fenchone.
The fronds are the mildest part: fresh, green and gently aniseed, softer than dill and without its tang. The stalks are more fibrous and more strongly flavoured. Fennel pollen is the most concentrated of all — sweet, honeyed, a little like liquorice and saffron together — and is used by the pinch. Heat quickly dulls the fronds, but dried wild fennel stalks and seed heads stand up to long cooking and grilling. See aroma-compounds.
In the kitchen¶
Fennel's great affinity is with fish and pork, and it is the herb of the Mediterranean coast.
- Sicily — pasta con le sarde: fresh sardines, wild fennel, salted anchovies, raisins, pine nuts, saffron and onion, tossed with bucatini and topped with toasted breadcrumbs (muddica). The wild fennel is blanched and its cooking water used to boil the pasta. Outside Sicily, the fronds from Florence fennel with a pinch of fennel seed make a reasonable stand-in.
- Provence — fish over fennel: loup au fenouil, sea bass grilled or baked on a bed of dried fennel stalks, which scent the flesh; fennel fronds go into fish soups and herb mixtures for the grill, and fennel is a usual part of bouillabaisse.
- Tuscany — finocchiona: the soft, coarse pork salami of Florence and Siena, flavoured with fennel seed and often wild fennel flowers; it has held protected (PGI) status since 2015. Fennel pollen is rubbed into porchetta and roast pork.
- Greece and Crete: wild fennel (maratho) goes into marathopites, fennel and greens pies, and into stews of pork, beans or snails. See greek-cuisine.
- Northern China: fennel fronds (huixiang) are chopped with pork as a filling for jiaozi dumplings, a classic of Beijing and the north-east.
- Everyday: chopped fronds in salads, potato salad, mayonnaise, butter for fish, and scattered over roast fennel or tomatoes. Use them as you would dill.
💡 Fronds are a bonus
Florence fennel bulbs usually come with a green tuft. Don't bin it: chop it into a salsa verde, a dressing for the fennel itself, or over grilled fish.
Add fronds at the end, and use pollen by the pinch as a finishing seasoning.
Buying and storing¶
Fronds wilt fast. Keep them, or the bulbs they came on, wrapped in damp paper in a bag in the fridge and use within two or three days. Chopped fronds freeze reasonably in butter or oil for cooking (see freezing-herbs); dried fronds lose most of their flavour.
Stalks and seed heads dry well: hang them in bundles in late summer, then keep them for laying under fish or on the barbecue (see drying-herbs). Keep fennel pollen in a small, airtight jar away from light; it fades within about a year.
Substitutes¶
dill is the closest fresh substitute, though it has more tang and less sweetness. For cooked dishes, a pinch of crushed fennel seed gives the aniseed note without the green freshness. chervil or a little tarragon can stand in for fennel fronds in sauces and with eggs. There is no real substitute for fennel pollen, though finely ground, lightly toasted fennel seed goes some way.
Pairs well with¶
Fish (especially oily fish such as sardines and mackerel), shellfish, pork, sausages, olive oil, lemon, orange, tomatoes, potatoes, white beans, raisins, pine nuts, saffron, garlic, chilli flakes, parsley, dill and black pepper.
Growing your own¶
Herb fennel is one of the easiest perennials to grow: give it full sun and well-drained soil and it will thrive for several years, dying back in winter and returning in spring. Sow direct from April to June, or buy a plant; it develops a long taproot and moves badly once established. One or two plants are plenty, and bronze fennel is handsome enough for a flower border.
Cut fronds regularly from spring onwards. Let some stems flower in summer for pollen (shake or tap the open flowers into a paper bag, then sieve) and seed. Fennel self-seeds generously, so remove seed heads you do not want. Keep it well away from dill: the two cross-pollinate, and seedlings from either will be muddled. Florence fennel is a fussier vegetable crop that bolts in heat or dry soil. See planning-a-herb-garden.
Health and safety¶
Fennel is safe in culinary amounts. Like tarragon it contains some estragole, and concentrated fennel oils and large quantities of fennel tea are not recommended for young children or in pregnancy. People allergic to celery or carrot sometimes react to fennel (see spice-allergies).
Foragers should be careful: hemlock and other poisonous members of the carrot family grow in the same places. Wild fennel's strong aniseed smell, fine thread-like leaves and yellow (not white) flowers are good pointers, but never eat any wild umbellifer you cannot identify with certainty. See poisonous-lookalikes and foraging-wild-herbs.