Introduced species: Fennel (Foeniculum vulgare)
Characteristics: Fennel is a perennial herb of the carrot family, with finely-dissected green leaves–similar to those of dill– and a strong anise scent. Leaves and seeds of this plant are used in cooking; some varieties have a large, bulb-like base to the stem, which is also eaten. Fennel may reach up to 6 feet in height. Flat-topped clusters (umbels) of small yellow flowers bloom in early summer, and give way to small, brown-green seeds that turn gray as they age (these are the seeds often used as a pizza topping, in sausage, etc.).
Note: Please triple check your plant ID before consuming any plant materials.
Spread: Fennel spreads fairly abundantly by seed; fennel seeds germinate readily in Oregon’s soils and climate, allowing this plant to crop up in natural areas and open spaces if it is not kept under control. Native to the Mediterranean region, it was introduced here for culinary uses.
Control: Preventing seeding is key to controlling the spread of fennel. Flower heads can be cut off as they form (and used for their fabulously flavored pollen!), or the plant can simply be dug up if it is not wanted.
Native replacement: Yarrow (Achillea millefolium) is an easy-to-grow native plant with similar foliage to fennel that will do well in the same sorts of habitats. While not especially tasty, it does have medicinal properties; it is particularly useful for stanching bleeding from shallow wounds. And the bees love it!