Herbaceous plants - biennial

Index for herbaceous noxious weeds with a two-year life cycle in King County.

Biennial plants have a two-year life cycle. This means they will germinate, grow, reproduce and die within two years. Biennial plants start from seeds then typically grow and stay as rosettes (low growing circular cluster of leaves) their entire first year, lying dormant over winter. then grow a taller stalk the second year (AKA bolt) before they flower, go to seed, and die.

If the weed infestation is overwhelming and you aren’t sure where to start, focus on the second-year plants before they go to seed! The rosettes won’t spread for another year, and tackling the second-year plants ensures the infestation doesn’t get any bigger.