Coastal Invasive Species Committee


Common Fennel

Foeniculum vulgare






 Family:  Apiaceae  

Other Common Names: Sweet Fennel

Origin:  Southern Europe

Habitat:  Open disturbed areas including: roadsides, fields, grasslands, riparian areas, wetlands

Status:  "Alert" Species; gardeners should avoid planting or purchasing Common Fennel

Impacts:  Disturbed soil encourages the growth of dense stands which may exclude native vegetation.  Some regions in Australia categorize Fennel as a noxious weed.

Description:  Fennel is a perennial with a thick taproot.  They can grow to be as tall as 10 feet.  Foliage and seeds have a strong licorice or anise scent.  Inflorescence consists of several flat umbels with small yellow flowers.  Plant reproduces by seed primarily, being dispersed via water, soil movement, animals, or human activity.  

Management Strategy:  Chop small infestations.  Slashing right before flowering may kill the plant.  Even if the plant recovers, slashing the stems at flowering will prevent the seeds from setting.  Digging out plans individually is possible, but will be very labour-intensive due to the deep taproot.  There are no biological control agents for common fennel.  2,4-D and Glyphosate are effective herbicides.