Japanese knotweed
Japanese knotweed is increasingly present in our territory, and we must take action to prevent its spread.
Photo : ©CSBVLD
Pilot Project:
2025 Tarping Operation
In June 2025, the CSBVLD team tackled a colony of Japanese knotweed located near Lake Davignon. This invasive exotic plant was a major concern for the CSBVLD due to its close proximity to the lake.
After consulting with experts in invasive species management and observing regional control projects, the CSBVLD was equipped to proceed with the eradication of this Japanese knotweed colony. The plant was cut, left on the ground, and then covered with a membrane (tarp) spanning the entire area. The tarp must remain in place for a minimum of 5 to 7 years, and continuous monitoring will be required. A sign will be installed on-site to inform the public about the project.
Japanese Knotweed
Japanese knotweed is an invasive exotic species that spreads rapidly and threatens our ecosystems.
Watch this video to learn more about this species, how it spreads, and its impacts. (MELCCFP)
Signs.
A sign will be present near the intervention area.
Description.
Japanese knotweed is an invasive exotic plant native to East Asia.
It is a fast-growing perennial herb often found on residential properties as an ornamental plant. It colonizes a wide variety of soils and prefers open areas such as:
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Shorelines
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Roadsides and railways
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Fallow land
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Gardens
The formation of dense colonies prevents the growth of other plant species, resulting in very low biological diversity in invaded environments. Japanese knotweed can also promote shoreline erosion and alter the chemical composition of the soil, as well as the diversity of microorganisms found within it. It restricts access to shorelines and blocks openings that provide views of the landscape. Furthermore, its roots and stems can infiltrate cracks in infrastructure. (MELCCFP)
Copyright©CRELaurentides
Report the presence of Japanese knotweed!
If you see a new area infested with Japanese knotweed, please report it.
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Warn the Government of Quebec using Sentinelle
Sentinelle is a free tool that allows people to report the presence of invasive exotic species in Quebec and simplify their detection. Find it here
