As a culinary herb, fennel (Foeniculum vulgare) is grown for its licorice-flavored seeds—a prime ingredient in Italian sausage and curries—and for its leaves, used in salads and fish dishes. Another variety (F. vulgare var. azoricum) yields finocchio, also known as Florence fennel. This plant is raised for its bulbous leaf base, which is eaten raw or cooked.
Grow fennel in well-drained soil in a sunny location; in hot areas, provide partial shade. If conditions are right, fennel will self-sow readily, so watch for volunteers.
Fennel’s lacy foliage and dainty flower heads make the herb handsome enough to deserve a spot among ornamentals. Mix it with roses and lavender, for example, or with any plant that has blue-green leaves, such as dianthus. While finocchio is half-hardy, a heat wave can cause it to bloom without forming a bulb. In the North, sow seeds indoors and set seedlings out two weeks before the last frost date; protect from late spring freezes. In the South, sow seeds in July to harvest bulbs in October.
For white, tender bulbs, cover the young plants up to their necks with soil when you bed them out; water regularly. Once the bulb begins to form, cover with more soil. Harvest after three weeks. In moist climates, take care that the bulbs don’t rot.