Common fennel

Foeniculum vulgare

fennel leaves.jpg
fennel base.jpg

Common Fennel - A large perennial herb that grows to be about 6' tall, smells strongly of licorice, and spreads via seeds and pieces of the root crown.

Leaves: Dark green or bronze feather-like, deeply lobed and somewhat spindly, the leaves are completely hairless and attachment points (petioles) are fleshy with a wide base.

Flowers: In bloom from May to September, the small yellow flowers form an umbrella shaped cluster (umbel) and resemble those of poison hemlock and wild chervil.

Habitat: Can establish in just about any habitat from roadsides, to prairies, to coastal bluffs, to wetland areas.

Weed Classification: B Designate

Why is it a Noxious Weed?
Due to its tendency to escape cultivation and quickly create very dense infestations that crowd out native plants, Common fennel is particularly threatening to wildlife habitat including native grasslands.

Lewis County Noxious Weed Control knows of a small number of Common Fennel plants in the county. Please report any found. Make sure you are not confusing with Annual (bulbing) fennel. Send us a photo if you are unsure.

Annual (Bulbing) Fennel has a clearly visible bulb at its base:


Control Recommendations:
WA State Noxious Weed Board
PNW Pest Management Handbook
UC Davis Weed Report