Invasive Species

Invasive Species, in this context, are plants or animals that have been introduced to an area from somewhere else. They lack the natural predators and diseases which keep them in check in their native habitats. Invasive species also often have special traits that allow them to reproduce and spread prolifically, and colonize degraded or disturbed habitats (for invasive plants, this is often places such as roadsides and creek banks). This gives these alien species an edge, allowing them to easily out-compete native plants and animals.

Multiple invasive species have found their way into the Township of Langley that pose a risk to the health and safety of people, animals, property, and the environment. Some of them, like Japanese Knotweed, are listed as Noxious Weeds under BC’s Weed Control Act. As per the Weed Control Act, property owners have the responsibility to control these species on their property.

Japanese KnotweedRoadside Japanese Knotweed

Among the worst invasive plant species locally is Japanese Knotweed. This plant has the potential to ruin homes, roads, parking lots, sewerage, and water main infrastructure. 

With its green leaves and cluster of white flowers, you wouldn’t know just by looking at it, what a hazard Japanese Knotweed can be. With this plant, the threat lies beneath the surface -- in its strong and aggressive root system. Japanese Knotweed grows very quickly and reproduces in several ways, making it difficult to control. Digging or mowing it can disturb its roots or shred its stalk, causing the plant to grow and multiply. In fact, Japanese Knotweed can grow up to 3 metres (10 feet) in just one season!

Japanese Knotweed

To learn more about Japanese Knotweed, visit the websites below:

Japanese Knotweed Control Strategy

Do Not Mow sign

The Township of Langley is working to eradicate the threat of Japanese Knotweed from our roads and parks. You may see markers along various roads in the Township identifying where Japanese Knotweed is located. Do not mow these areas. Improper removal of the plant, such as mowing, could result in Japanese Knotweed multiplying.

The Roads Department is using a mild herbicide spray containing glyphosate to control Japanese Knotweed on road right of ways. The removal process is slow and tricky because it will take several treatments and inspections over the course of several years to ensure the roots are killed. When the roots are dead, the stock of the plant is cut and left on-site to dry. It is then transported offsite and buried up to 5 metres deep in one of the municipal operations storage pits.

In our parks, several patches of Japanese Knotweed have been identified and sprayed with herbicide. All sites designated for treatment are marked with signs indicating the date and type of treatment used. The Parks Department will continue to monitor and spray those areas until the threat of the invasive plant has been eradicated. Areas deemed to be free of knotweed after a number of successive years of no detection will be planted with native species to reduce the likelihood of the area being recolonized by invasive plants.

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