Fennel

Three crops, one plant

Fennel produces three distinct edible products from the same plant:

1. Bulb (Florence fennel) — the swollen leaf bases at ground level. Crunchy, anise-flavored, eaten raw or cooked.
2. Fronds — the feathery green leaves. Used as a herb, like dill (a relative).
3. Seeds — produced when the plant bolts to flower. Sweet, intensely anise-flavored, used as a spice and digestive.

Most cultivated fennel is grown for one of these three; “wild fennel” (the original Mediterranean form) produces all three but smaller bulbs.

The anise puzzle

Fennel, anise, and licorice all share a similar sweet-licorice flavor — but they’re different plants. They share the compound anethole, which is responsible for the flavor. Other plants with anethole include: tarragon, basil (Asian varieties), star anise (a tree of a different family), and some types of chervil.

Despite the overlapping flavor, the plants don’t substitute well for each other in cooking — anise has a sharper, more concentrated taste; fennel is gentler and more vegetable; tarragon adds anise notes plus its own grassy character.

A digestive

After meals in Indian restaurants, you’ll often find a small dish of fennel seeds (sometimes coated in sugar and food coloring as mukhwas). The seeds aid digestion — they relax intestinal smooth muscle and reduce bloating, properties documented in pharmacological studies. They also freshen breath, which has its own social value at the end of a meal.

In Italian sausage

Italian sausage gets much of its identity from fennel seed. The Tuscan salami finocchiona is named for the herb (finocchio); it was developed in the 14th century when affordable salt was scarce, and fennel seed both flavored and helped preserve the meat. Fennel pollen — the most concentrated form — is a luxury seasoning that costs hundreds of dollars per pound.

A garden warning

Fennel is allelopathic — it produces compounds that suppress the growth of nearby plants. It particularly inhibits beans, tomatoes, and dill (its close relative, with which it can also cross-pollinate, producing offspring of unpredictable flavor). Grow fennel away from the rest of the garden, in its own bed.