This large invasive species has been found in Edmonton for the first time
A large invasive plant species has been confirmed in Edmonton for the first time, being found on a private residential property last year.
The Alberta Invasive Species Council says what was first thought to be a new location of Japanese knotweed in 2025 has now been DNA confirmed as giant knotweed (Reynoutria sachalinensis, formerly Fallopia sachalinensis).
Alberta Invasive Species Council/Facebook
The plant was found on private residential property within Maple Ridge, and it’s not known how it arrived, but the council says it most likely was intentionally introduced as an ornamental plant through purchase (online or in-store) or transplant. Currently, there are no known populations in Edmonton’s natural areas or public properties.
Alberta Invasive Species Council/Facebook
Alberta Invasive Species Council/Facebook
Once established, giant knotweed spreads aggressively through underground rhizomes, forming dense stands that damage infrastructure like concrete and asphalt, crowd out native vegetation and are incredibly difficult and costly to remove.
Giant knotweed is the largest of the knotweed species and is listed as a “prohibited noxious on the Weed Control Act, so it must be eradicated,” the council added in a post to its Facebook page.
According to the Invasive Species Centre, giant knotweed can reach anywhere between 10 and 20 feet in height, and has been found in several Canadian provinces already.
If you think you’ve spotted giant knotweed, you’re asked to stop and take clear photos of the plant, record the location, and report it using the free EDDMapS app.