Japanese Knotweed

Japanese Knotweed is amongst the most difficult plants to control. This plant has the potential to impact homes, roads, parking lots, and other infrastructure.

It can grow to 3m (10ft) tall, resembling bamboo. Leaves are shovel shaped while the canes have characteristic purple flecks and die back to ground level in winter.

What the City of Chilliwack is doing about Japanese Knotweed:

  • Public education and outreach with the goal of reducing the spread of Japanese Knotweed and other invasive plants.
  • The Environmental Services Department is mapping locations of Japanese Knotweed. This information is used to help inform various management activities such as  avoidance by roadside mowers, contractors, and developers.
  • A contractor is using herbicide to control Japanese Knotweed in priority areas of public property. Control is difficult and slow as it can take several treatments and inspections over multiple years to ensure the roots are killed.
  • The City is collaborating with other local and regional governments, as well as environmental organizations, to develop effective and coordinated control programs in our region.

How can you control Japanese Knotweed?

Residents that have confirmed patches of Japanese Knotweed on their property can consider the following control options:

  • Never dig, mow or weed-eat Japanese Knotweed. This will only make the problem worse as knotweed can regenerate from stem and root fragments as small as 1cm3.
  • Follow the Best Management Practices for controlling Japanese Knotweed. 

To learn more about Japanese Knotweed or other invasive plants, call the City of Chilliwack’s Environmental Services Department at 604.793.2907 or visit the websites below:

Fraser Valley Invasive Species Society

Invasive Species Council of BC

Provincial Invasive Plant Program

Fraser Valley Regional District: Invasive Weeds

Description Date File Size
Japanese Knotweed Best Management Practices 2019-06-11 8.50MB