Invasive Plants

Tree bark with Invasive Species

Invasive Plants

Invasive plants are those introduced from other regions and have the potential to negatively impact humans, animals and/or ecosystems.

We don’t consider all introduced plants invasive or harmful. Invasive plants can establish quickly and spread rapidly in new areas. You may also hear them called noxious weeds. Noxious weeds are harmful to animals or people. It is also a term to describe legally designated species within the B.C. Weed Control Act.

Please report any species of concern to us. We especially want to hear about those on the prevent or eradicate lists. See below.

Priority Invasive Plants in Saanich

We work with regional and provincial partners to track the status and priority of invasive plants in our region.

The Capital Region Invasive Species Partnership (CRISP) Spotted Knapweedmaintains a Regional Priority Invasive Plant Status list. Saanich adapts this list for management planning. Find specific plant species information on our Invasive Resources page.

Saanich has a Noxious Weeds Bylaw. This requires landowners to control invasive plants and noxious weeds on private lands.

We have a Knotweed Stewardship Program which provides support and free treatment for Knotweed outbreaks on private property in Saanich due to the difficult nature of treating invasive Knotweeds and the high risk of impacts to our region. Combined with treatment on public land by Saanich Parks, knotweed has been reduced by nearly 70% since the program began in 2010! 

How We Manage Invasive Plants

Saanich, CRISP and other provincial partners use four categories to manage invasive plants:

  • Prevent
  • Eradicate
  • Contain
  • Control

We include a few examples from our region’s priority plants in each category below. There are many other invasive plants.

View the CRISP List to see the full regional list of priority plants.

Eradicate List

“Early Detection Rapid Response” is an important part of invasive management. We work to eliminate and control new invaders before they become wide-spread and have major impacts. The eradicate list identifies high priority new invasions or small enough populations that we can still eradicate them from an area or region.

Examples in Saanich:

Contain ListYellow Flag Iris

The contain list includes plants that are too established in some areas to eradicate, but are a priority to prevent spread to other areas. In Saanich these also include species of special concern like those with human or animal health impacts.

Examples in Saanich:

  • Yellow Flag Iris  Iris pseudacorus  (Alert Sheet)
  • Gorse Ulex europaeus (Alert Sheet) 
  • Poison Hemlock  Conium maculatum (Alert Sheet)
  • Purple Loosestrife  Lythrum salicaria (Alert Sheet)
  • Golden Willow  Salix alba var. vitellina

Control ListScotch Broom

Most know about established invasive plants like English Ivy and Scotch Broom. These plants are still a concern, but we can’t eliminate them from our region. We focus our management of these species on:

  • control in high value conservation areas.
  • public education to avoid further spread.

Community volunteers with the Pulling Together Program help manage these control list species.

Examples in Saanich:

  • Scotch Broom  Cytisus scoparius
  • English Ivy  Hedera helix
  • English Holly  Ilex aquifolium
  • Daphne / Spurge Laurel  Daphne laureola
  • Himalayan Blackberry  Rubus armeniacus
  • English Hawthorn  Crataegus monogyna
  • Periwinkle Vinca major, V. minor

While we have well-established invasive plants in Saanich, we need to keep them from spreading further. We also need to protect sensitive natural areas from them.

Property owners can help:

  • Control invasive plants on your land.
  • Properly dispose of garden waste and invasives.

To learn how to control some of our most established weeds, download our brochure:

To properly dispose of invasive plants, go to our Invasive Plant Disposal page.