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Invasive Plant Species

Have you ever wondered exactly why BC can claim to be  “Super Natural BC”?


A major reason lies in our biodiversity and the fact that BC is home to more species of plants and animals than any other province.

BC is home to:

 72% of Canada’s land mammal species

 50% of Canada’s amphibian species

 60% of Canada’s plant species

 70% of Canada’s nesting bird species 


In scientific terms, biodiversity is known as a supporting ecosystem service, because having great biodiversity improves everything else around us. The number of native plants and animals that we have around us improves the food we eat, the air we breathe, and the water we drink.

Invasive Species are the second greatest threat to biodiversity after habitat loss


The topic of “Invasive Plant Species”(IPS) is heavily indebted to the information published by the Invasive Species Council of BC and their Webinar “Invasive Species and Your Lake - Protect BC’s Waters.” 


The following video by the  BC Ministry of the Environment provides a quick 2 minutes on some basic ideas.  

Are Invasive Plants the Same as Weeds? No. A weed is commonly thought of as an unwanted plant in a given area, such as a vegetable garden or lawn.

What Makes a Species “Invasive”?


An invasive plant is a plant that when transplanted from its native habitat, grows aggressively, and out-competes and displaces desired vegetation.


Most invasive species are unintentionally introduced by human activities into places outside their native habitat.


Once they’re removed from natural predators and diseases invasive plants often reproduce, spread and survive better than native species.


Why are These plants so Successful?


Globalization through increased trade, transport, travel and tourism will inevitably increase the intentional or accidental introduction of organisms to new environments, and it is widely predicted that climate change will further increase the threat posed by invasive species.


With few limits on their populations invasive plant species can easily take over sensitive ecosystems permanently upsetting the balance of plant, insect, bird and other animal life. 


Most species have predators in their natural range that keep their population numbers in check. When new species are introduced, however, they typically come without their natural predators.

Most invasive species produce copious amounts of seed that often remain viable for great lengths of time. This seed is often bird or wind-dispersed, allowing it to cover great distances.


Some invasives have aggressive root systems that can spread long distances from a single plant. These root systems often grow so densely that they smother the root systems of surrounding vegetation.


Some species produce chemicals in their leaves or root systems, which inhibit the growth of other plants around them. For example, diffuse knapweed (Centaurea diffusa) emits a toxin called catechin into the soil that can kill native plants.


Most invasive species grow quickly and capitalize on sunlight, space, and soil, thereby “shading out” and reducing or halting the growth of native vegetation.


Many invasive plants are still sold in garden centres and are not labeled as being invasive. Gardeners tend to purchase invasive plants because these plants are attractive, tend to grow quickly and are shade tolerant.


Most invasives thrive on disturbed soil, on and around new developments, or along transportation and utility corridors.


What Kind of Impact(s) do Invasive Species Have?


A healthy plant community has a variety of herbs, shrubs, and trees. However, invasive plant species are capable of spreading quickly,  displacing native plants, preventing native plant growth, and creating areas completely dominate by one plant species (monocultures).


Monocultures of invasive plants degrade our natural environment by:

  • reducing soil productivity.

  • Impacting water quality and quantity.

  • degrading range resources and wildlife habitat.

  • threatening biodiversity.

  • altering natural fire regimes.

  • introducing diseases.


The economic impact of invasive species in Canada is significant. According to Environment and Climate Change Canada:

  • The estimated annual cumulative lost revenue caused by just 16 invasive species is between $13 to $35 billion.

  • Invasive species that damage the agricultural and forestry industries results in an estimated $7.5 billion of lost revenue annually.

A Few Examples of Invasive Plants in our Area

Yellow Flag Iris, (Iris pseudacorus)

 Yellow Flag Iris is an easy to grow perennial bulb native to Europe, Western Asia and North Africa. It was first introduced to North America in the 19th century as an ornamental plant for ponds and water gardens. Its showy yellow flowers  perform best in wet soils.  It can grow in water up to 10 inches deep or the wet muds along a pond or lake.


Yellow Flag Iris can be toxic to humans and animals and cause human skin irritations.

Yellow Flag Iris invades ditches, wetlands, streams, lake shorelines, and shallow ponds. This plant reproduces through seed dispersal, horizontal roots, and when pieces of the roots break off, which can form new plants. The seeds float on the water in spring and fall, causing them to spread quickly. Several hundreds of plants may be connected underwater due to the extensive root system, which creates a thick mat that damages wildlife habitat, reduces water flow, and crowds out native vegetation.

Daphne (Spurge-Laurel)

Daphne laureola

Daphne is native to Europe and the Mediterranean area and was a popular ornamental plant in gardens at one time due to its glossy, rhododendron-like leaves and fragrant flowers. It is tolerant of both sun and shade and rapidly takes over native vegetation by forming dense thickets in a range of ecosystems. Its black berries are loved by birds, who spread its seeds.



Daphne is listed as a poisonous plant by the Canadian Poisonous Plants Information System, and as a toxic plant by Worksafe BC. Its toxic sap can cause skin rashes, nausea, swelling of the tongue, and coma.


Daphne has dark green, glossy, oval-shaped leaves that grow in a spiral pattern around the top of the stem. As Daphne gets taller, only the topmost section of the plant has leaves.

In the spring, clusters of tiny, fragrant, pale yellow flowers  form between leaf nodes (not at the tip of stems like other similar shrubs like rhododendrons). Flowering is followed by berries in late summer. The berries are black and poisonous to people and pets, but not to birds. Toxins exist in the sap, stem, leaves, and fruits.  Spurge-Laurel can reproduce via sucker roots (new plants may surface up to 5 m away) or by seeds.

Yellow Archangel

Yellow Archangel was introduced to North America from the temperate regions of Eurasia as an ornamental ground cover, prized for its unique silver variegated foliage and fast-growing nature. Today, this perennial garden plant is still used as ground cover but is more often seen in hanging baskets.


Yellow Archangel has a square-sided stem that grows from 30 cm to 60 cm in height. Small, yellow flowers grow in a clump close to the stem. Leaves are hairy, oval to heart-shaped, with toothed edges, and are dark green with an outer silver lining.


This plant prefers shady sites such as forested areas and grows in a dense mat that smothers native plants. It spreads by seed and plant fragments, and by animals and humans passing through the vegetation.


Yellow Archangel has now escaped into natural habitats throughout the Pacific Northwest, largely due to illegal green waste dumping when disposing of hanging baskets.

Sunshine Coast Regional District


In January 2015, the SCRD Board endorsed the establishment of the Invasive Species Technical Working Group (ISTWG). The purpose of the ISTWG is to provide a collaborative approach to invasive species management on the Sunshine Coast, raise awareness of the need to manage invasive species, and to bring together different levels of government, First Nations, and stakeholders with unique mandates and different jurisdictions on the Sunshine Coast. Members of the ISTWG include representatives from the SCRD, shнshбlh Nation, Town of Gibsons, District of Sechelt, Coastal Invasive Species Committee, Ministry of Transportation and Infrastructure and Vancouver Coastal Health. The ISTWG meets quarterly.


Whether grown as ornamentals or along road corridors, invasive plants have established themselves and are spreading on the Sunshine Coast. The SCRD would like to prevent the introduction of new species of invasive plants, and to reduce the spread of existing infestations to minimize the impacts on lands within the Sunshine Coast.

On January 22, 2015, the SCRD Board adopted a revised "Pesticide Use and Invasive Species Management Policy". To view the SCRD Board policy please click here.


When gathering information and sharing it with you, it is important to make it as easy as possible to access the information you need.  While you can go the SCRD website page, (click on "INVASIVE SPECIES MANAGEMENT" ), the information on that page is a bit hard to navigate. Instead we have taken their "CURRENT LIST OF PRIORITY INVASIVE PLANTS FOR THE SUNSHINE COAST" from the SCRD page and re-produced it in an easy to use format where you can get instant access to detailed information on each plant. Just click on any plant named below.

Scotch Broom

increases wildfire fuel loads and escalates

wildfire intensity


As you become more proficient in identifying invasive plants, the next step is to become proficient in reporting what you have found and thereby add to an invasive species data base and associated mapping service. 


An earlier cellphone tool called "Report-A-Weed" has been discontinued and replaced with a much more useful application called "Report Invasives BC".  Here is the application's logo, "IAS", which stands for Invasive Alien Species

As the "IAS" name implies this reporting tool covers the wide spectrum of invasives from Mammals, Fish, Birds, Amphibians & Reptiles, Insects& Spiders, Other Inverebrates, Terrestrial Plants, Aquatic Plants and Other/Unknown species. Any report you make is based on a photo, taken by you, along with associated data that you enter and then"Submit Report".  It's as simple as that. 

To find and download the IAS application click here for Android and here for Apple and do the simple download.

If you prefer to report an invasive species using an online form then simply use this button:


So where does all this data end up?  The Invasive Alien Plant Program (IAPP) Map can show you the reported sites of invasive plants in BC. This database includes sites reported by government agencies, non-profits, and the public.

So now that you have found an invasive plant, identified it, and dug it up, how do you get rid of it safely? of the easiest ways for each of us to counter the spread of invasive plants is to be rigorous about how and where we get rid of our garden waste. Green waste dumping information for our area may seem complicated but at least it makes environmental sense.




The following invasive species are not accepted as part of the SCRD's green waste recycling program.


  • Giant Hogweed – accepted as garbage at the Sechelt Landfill (must be secured in clear bags); garbage tipping fee applies

  • Scotch Broom - accepted as garbage at the Sechelt Landfill (must be secured in clear bags; no flowers or seed pods); garbage tipping fee applies

Not Accepted:

  • Knotweeds

  • Leafy Spurge




If you have an infestation of invasive plants on your property, professional help may be the only way to get a handle on it. A qualified and experienced contractor will be able to advise you on a variety of techniques based on your particular site and situation.

Keep in mind that dealing with invasive plants requires persistence! A small patch of Knotweed, for example, requires a few rounds of treatment, possibly over a few years, before it is eradicated.

Search the yellow pages for 'Landscape Contractors'. Here are some questions to ask when shopping around for a contractor:

  • Do you have experience dealing with invasive plants, particularly Knotweed?

  • What methods do you use?

  • Do you have the appropriate license and permits to apply herbicide? If so, what kind of herbicide might you use and what do I need to be aware of?

  • What is your disposal plan for any plant parts, to prevent further spread?

  • Does your price include monitoring or follow-up visits?

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