This week’s “I Spy” is one that the members of our Field Crew know all too well, as they spend a significant portion of their time treating it.
Japanese Knotweed is the plant with the reputation that precedes it. Originally from Eastern Asia, Japanese Knotweed was introduced to British Columbia as a garden ornamental in the 1900’s and it has caused all sorts of problems since!
Japanese Knotweed is a perennial that can be identified by its bamboo-like stems that can grow to be 1 – 5 m tall. It reaches such heights over the span of a single season, since the shoots die back each winter. Japanese Knotweed has large, egg-shaped leaves and small, white flowers that bloom in the late summer. When Japanese Knotweed begins to sprout, its shoots look like greenish-red asparagus growing right through the soil.
In its native range, Japanese Knotweed grows on harsh, volcanic slopes where it plays a role as a colonizing species. In BC, it can be found growing through concrete, damaging buildings, bridges and roads and can grow at a rate of 1 m per week creating large areas of invasive plants! Japanese Knotweed also negatively impacts ecosystems by out-competing native plants and forming dense stands along riverbanks, which die back in winter, exposing soil to erosion. When this happens, root fragments can get sent downstream which leads to further infestations.
Japanese Knotweed is a major issue in the Sea to Sky Corridor and reporting it helps to keep it under control. For more information, you can check out our Japanese Knotweed Resource Page. Remember to report it to either ssisc.ca/report, firstname.lastname@example.org or by phone at (604) 698-8334.