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Invasive Plants and Noxious Weeds

What are invasive plants?

Invasive plants are typically non-native plants or "weeds" that have been introduced to British Columbia without the insect predators and plant pathogens that help keep them in check in their native habitats. Without their natural enemies, these invaders are able to rapidly outcompete native plants, ornamental species and agricultural crops. The BC Government has classified some of the most harmful invasive plants as "noxious weeds".


What are their impacts? 

Invasive plants negatively impact our local environment and economy by:

  • reducing the agricultural productivity of our cropland and rangeland;

  • lowering real estate values;

  • endangering our health and well-being;

  • dramatically damaging some of the region's unique scenic values and tourism opportunities;

  • reducing water quality and fish habitat;

  • altering the composition and structure of native plant communities; and

  • destroying valuable wildlife habitat


Puncturevine in hand

How We Manage and Control Invasive Plants

SFI_seeding on Meadow RD_Weyco_Nov 2014_

Cultural Control

(Prevention and mitigation)

Jodie and Rachel_Adams Bird Sancuary_202

Mechanical Control

(Mowing, digging, pulling, cutting)

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Chemical Control


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(Natural insect enemies)

Priority Ranking of Invasive Plants

The Okanagan and Similkameen Invasive Species Society holds regular planning meetings to update the regional list of priority species for invasive plant management. This list helps guide inventory, treatment, monitoring, and data management for each field season. We currently have six categories:

Watch For - Poses a significant threat and does not presently occur in the region. Management objective - prevent establishment.

Regional EDRR (Early Detection Rapid Response) - Poses a significant threat (very high risk). Relatively new to the region and is very limited in extent. Management objective - eradicate if located.


High Priority - High risk/impact. Limited in population with significant potential to spread in the region. Management objective - contain to prevent further expansion. 

Medium Priority - Medium risk/impact. Limited distribution - broader population distribution with potential to spread further in a region. Management objective - control to prevent further expansion to protect unique habitats, agriculture, etc.

Low Priority - Low risk. May be widespread or not, may be of concern in specific situations with certain high values. E.g. conservation lands, specific agriculture crops. 

Biocontrol - Primarily treated with biocontrol agents or considered under successful biocontrol in the region (e.g. impacts are no longer significant). 

View our Priority Species List here

Plant profiles

Plant Profiles - Watch For

These are invasive plants that may occur in neighbouring jurisdictions, but are currently unknown within the RDOS. Please watch for and report sightings of these species. Click on a species for more information.

Plant Profiles - Regional EDRR

These are invasive plants relatively new to the region and very limited in extent. Please watch for and report sightings of these species. Click on a species for more information.

Evelyn Simak

Plant Profiles - High Priority

These are invasive plants limited in distribution that occur in isolated patches or in isolated areas within the RDOS. Click on a species for more information.

Joseph M. DiTomaso, University of California - Davis,

Plant Profiles - Medium Priority

These are invasive plants that have a broader distribution with the potential to spread further in the region. Click on a species for more information.

Plant Profiles - Low Priority

These are plants that may be widespread and of concern in specific situations. Click on a species for more information.

Plant Profiles - Biocontrol

These are plants that are treated primarily by biocontrol agents (natural insect enemies).

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