Washington State Noxious Weed Control Board

Common Fennel, Foeniculum vulgare

Now a 2007 Class B Noxious Weed, designated in areas where it has not spread and in regions containing rare, native prairie land, which is susceptible to invasion by non-bulbing fennel. The designated areas, where control of this plant would be required, are as follows:
- Regions 3,4,6,7,8,9, and 10
- Region 1, except the incorporated areas of Port Townsend
- Region 2, except the incorporated areas of Anacortes and Mount Vernon
- Region 5, except King and Kitsap counties
Already a serious problem in California, common fennel has been colonizing in Oregon and western Washington. It is being listed because there is concern that it could invade our few remaining grasslands.
*Bulbing fennel, cultivated for the edible 'bulb' at the base of the stems is not being listed because this annual variety of fennel is not invasive.*
View the listing proposal and the Written Findings.
Have you seen common fennel populations where you live? We are seeking distribution information so that we can best determine which areas should be designated for control. Please contact us at noxiousweeds@agr.wa.gov or 360-902-2082, or contact your county weed control program.

Often planted as an ornamental for its feathery foliage, common fennel has been establishing wild populations that can be difficult to control.	Bulbing fennel, F. vulgare var. azoricum, does not pose a threat to grasslands, because it is an annual and because it is typically harvested as a vegetable.
Common fennel looks similar to dill; however, it has a distinctive anise, or licorice, aroma.	A close up of common fennel foliage.