Coastal Invasive Species Committee


Knotweed Resources

KnotonmyProperty snip

A Homeowners guide to defending their property from Knotweed invasion.

The Coastal ISC has partnered with other regional weed committees throughout BC to bring you these fun and educational resources to help you defend your property from Knotweed.   Visit the website which is full of videos, tips and a downloadable Booklet.

Knot on my property Cover thumbLearn more about:


Property Values and Legal Issues

What Knot to Do

Knot Anymore

Watch a Video and learn what is the big deal about Knotweed

                                       Download the PDF Booklet



knotweed header Photo Credit: M.Mohrs

Invasive Knotweeds: Japanese, Giant, Bohemian & Himalayan                         (Fallopia japonica, Fallopia sachalinensis, Fallopia x bohemica & Polygonum polystachum)

Knotweed Species are found throughout communities on Vancouver Island, the Gulf Islands and the Sunshine Coast.

These non-native, invasive species are listed by the World Conservation Union as one of the world's worst invasive species.

The invasive root system and strong growth can damage concrete foundations, buildings, septic systems, roads, paving, retaining walls and the environment.

Knotweed can easily take hold in riparian ecosystems, roadsides and waste places. It forms thick, dense colonies that completely crowd out all other plants. The success of the species has been partially attributed to its tolerance of a very wide range of soil types, pH and salinity. Its rhizomes can extend 7 metres (23 ft) horizontally and 3 metres (9.8 ft) deep, making removal by excavation extremely difficult.  Additionally even tiny root fragments can regrow into new plants.

The plant is also resilient to cutting, vigorously resprouting from the roots.



Additional Resources:

Knotweed Information Sheet - Nanaimo Region

Knotweed Information Sheet - Comox Valley Regional District

Summary Findings from Knotweed Workshop Held March 2015

Invasive Species Council of BC Knotweed T.I.P.S

“Key to Identification of Invasive Knotweeds in British Columbia" (2007).  BC Ministry of Forests and Range (PDF Document)