Common Fennel

common fennel

Foeniculum vulgare • Class B

Family Name: Apiaceae family  (ay-pee-AY-see-ee) 
Common: Carrot/celery family (formerly Umbelliferae)
Genus: Foeniculum (fen-IK-yoo-lum)  
Meaning: Diminutive form of Latin foenum, hay; referring to the smell
Species: vulgare (vul-GAIR-ee)
Meaning: Common



This licorice scented Mediterranean herb grows 4 to 10 feet tall. It has feathery, dark green to bronze colored leaves and umbrella shaped clusters of yellow flowers.

Bloomtime is from May to September. 

Foliage, stem, roots and seeds are hairless and all have a very strong licorice scent.

 Why Is it a Noxious Weed?

Common fennel forms dense infestations, out compete native plants, and reduces native wildlife habitat. Once established it is difficult to control, due to its strong competitive abilities and persistent seed bank. 

Where Does it Grow?

It is found in disturbed sites such as roadsides, embankments, and vacant lots. It also easily colonizes grasslands and along waterways, wetlands, and streams. 


Common fennel infestations are becoming more common in Pierce county.

Mature fennel plants are difficult to remove due to the large tap roots which can reach depths of up to 10 feet. The plant can reestablish itself from small pieces of roots or bulbs. Bulbing fennel, (also known as Florence fennel, F. vulgare azoricum) does not pose a threat and is not an invasive problem, or listed as a noxious weed in Washington state.

It reproduces by seed and vegetative root buds.  A single plant can produce thousands of seeds during its 1st year of growth and more than 100,000 in subsequent years. 

Control Options:

More Information:

For more information on this noxious weed Download our Flyer or visit Washington State Noxious Weed Control Board Here.  Photos by Rebecca Shoemaker, Pierce County Noxious Weed Control Board.

More Pictures:

common fennelcommon fennelcommon fellel in pierce county noxious weed