Fennel is a herbaceous perennial and a member of the carrot family, Apiaceae, that also includes celery, sea holly, and dill. It is native to the shores of the Mediterranean but has naturalized in the US where it grows along roadsides, in pastures and in other open sites. The plants grow 4- 8’ tall and have hollow stems bearing 16” long dissected yellow-green leaves with thread like segments. Twenty to fifty tiny yellow flowers appear in terminal compound umbels 2-6” wide in mid to late summer and give way to aromatic seeds heads. Leaves and seeds have an anise like flavor and aroma and are used in cooking. Fennel is also a food plant for the larvae of some swallowtail butterflies. Plants are attractive garden plants and are especially valuable in an herb and butterfly gardens. The genus name, Foeniculum, comes from the Latin word faeniculum, a diminutive form of faenum meaning hay. The specific epithet, vulgare, is the Latin word meaning common.
Type: Perennial herb.
Bloom: Large umbels of small yellow flowers are produced in summer.
Foliage: Finely dissected deep green leaves. Bronze-leaf variety available also.
Size: 4-5’ H x 2-3’ W.
Light: Full sun.
Soil: Organically rich, moist, well drained.
Hardiness: Zones 4-9.
Care: Clip leaves for use once the plant is established and freeze for later use if desired. Harvest seeds when they turn from yellowish-green to brown by clipping the flower heads and placing them in a bag stored in a warm dark place until the seeds are completely ripe, then store in jars. When using leaves in cooking add them at the very end of the cooking time as heat destroys their flavor.
Pests and Diseases: None of significance but plants may be susceptible to root rot in poorly drained soils, aphids, and slugs.
Propagation: Seed (reseeds it self).
Companion plants: Fennel is allelopathic to some garden plants meaning that will inhibit or hurt their growth. Susceptible plants include bush beans, tomatoes, and kohlrabi.
Outstanding Selections: Foeniculum vulgare ‘Purpureum’ (bronze leaves).