Habitat

• While it is a newer invasive plant to BC, garlic mustard has been confirmed in the Great Victoria, Metro Vancouver, Fraser Valley, and Central and North Okanagan regions
• It is common in disturbed sites such as forest edges, fence lines, roadsides, trail sides, floodplains, and gardens
• Can quickly move into undisturbed habitats such as parks, forest understories and streambanks
• Plants are larger and produce more seeds in partial shade, compared to full shade or full sun
• Can tolerate a wide range of moisture and soil conditions

Impacts

Health & Safety

• Several of toxic chemicals (e.g., glycosides, phenolic acids, cyanide, and glucosinolates) have been found in leaf, stem, and root extracts of garlic mustard
• Dairy cows that eat garlic mustard leaves will produce tainted milk

Ecological

• Dominates understory plant communities, reducing biodiversity
• Produces toxins that suppress the growth of nearby plants
• Phytotoxins can persist in the soil for years
• Negatively impacts the life cycle of butterflies

Social & Economic

• Host to several fungi and viruses that can infect commercially grown members of the same plant family, such as broccoli and turnip 

Habitat

• One of the most widespread invasive plants in Metro Vancouver 
• Can grow on a variety of barren, infertile soil types, and a range of soil pH and textures
• Prefers soils with higher concentrations of sand, and less silt and clay 
• Tolerant of periodic flooding by brackish or fresh water
• Able to withstand soils with low water content and low nutrient availability with only a small reduction in growth 

Impacts

Health & Safety

• Contact with thorns can cause skin irritation, scratches and small wounds
• Large thickets obsturct sightlines and provides increased opportunities for criminal activity in residential areas adjacent

Ecological

• Large thickets can prevent the establishment of native vegetation
• Poorer quality habitat than native shrub species results in decreased biodiversity
• Associated with a statistically significant reduction in bird species 
• increased chances of erosion and flooding in riparian areas

Social & Economic

• Can obstruct roads, walkways and signage, making it difficult to access or inspect structures or other assets
• Limits the movement of people and large animals
• All levels of government, non-profit organizations and private property owners in Metro Vancouver spend significant resources managing it every year

Control Methods

Manual

• Young individual plants that are large enough to grip can be hand pulled
• Individual plants in sites of all sizes can be dug out
• Cutting 30 cm above the ground can be useful before digging out roots

Mechanical

• Mowing/tilling to remove exposed roots
• Labour intensive & must be repeated multiple times

Chemical

• Foliar application, basal bark spray, & cut stump
• Requires trained staff
• Unintended environmental/ health impacts

Cultural

• Growing a closed tree canopy
• Targeted grazing

Resources

Himalayan Blackberry Best Management Practices - August 2021

Himalayan Blackberry Fact Sheet - August 2021

Feasability of Targeted Invasive Plant Grazing in Metro Vancouver - Full Report

How to Stop the Spread of Invasive Plants brochure - Feb 2023

Photo Credit (in order of image appearance): Free the Fern Stewardship Society; ISCMV; ISCMV; Dawn Hanna; Free the Fern Stewardship Society; Free the Fern Stewardship Society; ISCMV

Habitat

• Native to the Caucasus region of Eurasia
• Was introduced into North America in the early 1900s
• In British Columbia, giant hogweed has been detected in the Southwest coastal and island regions, and recently reported in the Kootenays
• In Metro Vancouver, giant hogweed has been found in 20 municipalities, Electoral Area A, and Tsawwassen First Nation lands 
• Grows in wet areas along streams and rivers, parks, forest edges, on waste ground, near houses, in gardens, in vacant lots, and along transportation corridors

Impacts

Health & Safety

• The sap contains furanocoumarins, which upon contact with skin, can result in dermatitis 
• Furanocoumarins react with sunlight and cause severe burns on the affected skin areas when exposed to sunlight, resulting in blistering and recurrent dermatitis

Ecological

• Form monocultures with large standing biomass and extensive litter production
• May change the composition and species diversity of native plant communities
• Large infestations of giant hogweed can kill grass and other understory plants by shading
• Increases soil erosion along stream banks

Social & Economic

• All levels of government and private land managers incur management costs in the region every year
• In 2016, agencies represented on Metro Vancouver’s Regional Planning Advisory Committee spent close to $100,000 on giant hogweed control efforts

Control Methods

Manual

• Tap root cutting: for small infestations and often labour intensive
• Flower removal: doesn’t eliminate the safety hazard & does not kill plants

Chemical

• Spray-on foliar application: for high-density sites and requires trained staff
• wipe-on foliar application: sites with flew plants or when growing indispersed with native vegetation

Mechanical

• Use of power equipment: can increase risk of injury to workers, spreads seeds, contaminates equipment

Cultural

• Use of grazing herds: requires specially trained herds and special permits

Resources

Giant hogweed Best Management Practice Guide - August 2021

Giant hogweed Fact Sheet - July 2023

Invasive Species Disposal Options

Feasability of Targeted Invasive Plant Grazing in Metro Vancouver

Help Stop the Spread of Invasive Plants regional brochure - Feb 2023

Photo credit (in order of image appearance): City of North Vancouver; ISCMV; N. Page (x4); ISCMV (x3); N. Bergunder

Habitat

• Native to the Palearctic regions of Europe and Asia and from Ireland to western Siberia
• European fire ants prefer moist habitats with an average temperature greater than 6° Celsius
• Precipitation in affected areas usually exceeds 1000 mm/year 
• Moist riparian areas may be at risk throughout British Columbia 
• First recorded in British Columbia in 2010, and has since been detected in many communities in Metro Vancouver and on Vancouver Island

Impacts

Health & Safety

• Aggresively defend their territory by swarming and delivering painful, repeated stings to people, pets and wildlife
• Stings leave venom under the skin, which may swell, become red and painful for 30 to 120 minutes
• Itchiness can last for a week
• On rare occasions, stings can cause anaphylactic shock

Ecological

• Able to displace native ant species
• Infestations have been found to reduce chick survival in several bird populations in North America
• Also have the potential to impact agricultural crops 

Social & Economic

• Impacts for governments, businesses, non-profit groups and individuals in Metro Vancouver and across British Columbia
• Causes property damage to households, schools, municipalities, golf courses, public parks and green spaces  
• In 2016, agencies represented on Metro Vancouver’s Regional Planning Advisory Committee spent approximately $26,000 on European fire ant control efforts 
• There is also costs for private land owners and education and awareness activities

Control Methods

Manual

• Digging, torching
• Sites where use of insecticide is not an option
• Labour intensive, will not eradiate colonies, and may increase exposure to ant stings

Chemical

• Dig or expose the nests and apply the insecticide, Permethrin
• Place baits (2% boric acid in sugar solution) around the nests

Cultural

• Landscape alteration to reduce preferred habitat
• May reduce population density and prevent spread to new areas

Resources

European Fire Ant BMP - August 2021

European Fire Ant Fact Sheet - August 2021

Photo Credit (in the order they appear on the page): Sean McCann; USDA APHIS PPQ - Imported Fire Ant Station , USDA APHIS PPQ, Bugwood.org; ISCMV; Eli Sarnat Antkey, USDA APHIS PPQ, Bugwood.org; Gary Alpert, Harvard University, Bugwood.org; ISCMV

Habitat

• Hardy and adapted to grow in moist forests at low elevations in shade or sun
• Tolerant to a wide range of soil, moisture, temperature and light conditions
• Commonly found in mixed deciduous and coniferous forests, along the edges of wetlands and near residential areas
• Has invaded the south coast of BC, in the Fraser Valley and on Vancouver Island

Impacts

Health & Safety

• Leaves produce flammable vapour when heated, causing them to ignite easily, and infestations may pose a fire risk 
• Berries are toxic to humans, causing nausea, vomiting, abdominal pain and diarrhea if ingested 

Ecological

• Dominates tall shrub layers of forest understories, shading out and suppressing germination of native trees and shrubs
• Water and nutrient hog, which discourages other plants from growing in its vicinity
• Modifies soil conditions by depositing significant amounts of organic matter and sulphur

Social & Economic 

• Has the potential to impact the forestry sector
• Invasive in actively managed forests and clear cuts in the Pacific Northwest, spreading across and persisting through forest successional stages
• Prickly leaves can hinder human activity around English holly infestations

Control Methods

Manual

• Small to medium plants can be removed by pulling or digging 
• Labour intensive & must remove entire plant

Mechanical

• Cutting of medium to large plants can be done in combination with chemical methods
• Girdling is a relatively quick method of killing large plants without chemical methods

Chemical

• A certied trained professional can treat plants using herbicide
• Methods include: stump application, stem injection and basal bark application

Resources

English Holly Best Management Practice Guide - August 2023

English Holly Fact Sheet - August 2021

Help Stop the Spread of Invasive Plants brochure - February 2023

Photo Credit (in the order they appear on the page): ISCMV; Free the Fern (x3); USANPN Phenophases Flickr; Bjorn S Flickr; ISCMV; Free the Fern (x2); ISCMV; John Ruter, University of Gerogia, bugwood; Richard Beard; ISCMV

Habitat

• Commonly found in urban forests growing on the forest floor and up the trunks of canopy trees
• Found on rocks/cliffs, sunny fields, and in human-dominated habitats such as gardens and up fences, posts and walls
• Young plants are shade tolerant, enabling growth under existing dense stands of plants and trees

Impacts

Health & Safety

• Weight of ivy is capable of breaking branches and toppling trees, especially in conjunction with storm or disease events 
• Also serves as a reservoir for bacterial leaf scorch (Xylella fastidiosa)
• Berries are toxic to humans and many animals

Ecological

• Smothers native vegetation and may inhibit understory growth in riparian forests
• Ivy density is correlated with a reduction in species richness and changes in species composition
• Shallow root systems can also increase soil erosion
• Can engulf and encircle shrubs and trees,depriving bark of normal contact with air and microorganisms
• Can significantly impact native birds that are reliant on native forest structures

Social & Economic:

• Can consume fences & siding, leading to damage and destruction of property

Control Methods

Manual

• From trees: Using pruners or saws, cut ivy stems at chest height from around the tree before removing from the surrounding ground. Never pull down from a tree!
• Small infestation on the ground: Take a good hold of the vine and gently tug in the direction of growth, loosening the roots from the ground
• Large infestation on the ground: The ivy can be rolled in a continuous mat away from you, carefully cutting the ivy vines and loosening all roots with your hands as you roll 
• Mulch application: 30 centimetre thick layer of coarse, woody mulch overtop of groundcover ivy may prevent the regrowth of stems and root fragments

Mechanical

• Heat treatument: Use of a weed torch or similar tool
• Mowing: ivy infestations may be suitable in areas that are already mowed regularly but may increase the risk of spread by root fragments and clippings

Chemical

• May be successful on young, actively growing plants
• Herbicide application on mature plants may slow growth, but is unlikely to eradicate them
• The waxy leaves of ivy help it resist herbicide absorption and may increase risk to non-target plants via run-off
• Ivy is resistant to some commonly used pre-emergent herbicides
• Herbicide may prevent the germination of native seeds in the seedbank and, therefore, promote the reinvasion of other invasive species'

Cultural

• Shortduration, high-intensity goat browsing could remove enough aboveground biomass to minimize regrowth 
• Grazing opportunities may be limited in urban areas by municipal bylaws, the need for specially trained herds, and potential damage to sensitive ecosystems 

Resources

English and Irish Ivies BMP - August 2021

English and Irish Ivies Factsheet - August 2021

Feasability of Targeted Invasive Plant Grazing in Metro Vancouver

How to Stop the Spread of Invasive Plants (Metro Vancouver Brochure) - February 2023

Photo Credit (in the order they appear on the page): Free the Fern Stewardship Society; ISCMV (x 8 photos); Forrest & Kim Starr; Free the Fern Stewardship Society

Habitat

Habitat

• Often colonizes disturbed and natural areas, such as riparian areas, river gravel bars, rock faces, pastures, abandoned sites, and recently logged or burned forests
• Grows well in coarse-textured, nutrient-deficient soil
• Prefers full sun, but is also shade tolerant 
• Can also grow in challenging conditions such as pavement cracks and road and rail rights-of-way 

Impacts

Health & Safety

• Along transportation corridors, butterfly bush can impact safety by obstructing sightlines

Ecological

• Although advertised as a beneficial plant for pollinators, all varieties of butterfly bush only provide nectar for adult butterflies
• Do not provide crucial habitat or food for earlier butterfly life stages, such as eggs or larvae
• The use of butterfly bush as a food source by butterfly species may impact native plant pollination success
• Dense thickets can also displace native vegetation, especially willows and cottonwoods
• May also deplete the soil of nitrogen and phosphorous 

Social & Economic

• Competes with native plants that have cultural and spiritual significance for Indigenous Peoples
• In reforested areas, butterfly bush impedes growth and leads to mortality of saplings, increasing the costs of tree establishment 
• In New Zealand, where butterfly bush is considered invasive, it is estimated that this plant costs the forest industry $0.5 to 2.9 million annually in control and lost production

Control Methods

Manual/Mechanical

• Young plants can be pulled by hand when the soil is moist, making sure to remove as much of the roots as possible
• To remove larger plants, use a manually-operated tool (e.g. Weed Wrench©, Extractigator© etc) or cut stems and dig
• Soil disturbance should be minimized to prevent germination
• Cutting butterfly bush with loppers or a saw is not an effective method alone, as plants will regrow quickly
• "Cut cover', using a thick tarp or mulch, can be effective 
• Flower removal in June to July can prevent the spread of seeds but will not eradicate the plant
• Mowing is possible for young, green plants, but this is not an effective control method 

Chemical

Note: the use of herbicides is highly regulated in BC and a valid pesticide licence is required to apply most pesticides

• The ‘cut stump’ method involves cutting the stems and trunk then immediately applying herbicide to the freshly cut surface(s) with a paintbrush
• Foliar application (spraying) can be undertaken by hand or using a backpack sprayer, however large plants are less vulnerable to foliar application
• Basal stem application involves using a backpack sprayer with a flat fan or solid cone nozzle to apply herbicide around the entire base of the stem and roots

Disposal

• Stems, branch and root fragments left on the ground may re-grow and should be removed off site
• Debris piles that are not removed or treated to kill all seeds and plant fragments can become a concentrated source of new germinants the following season 
• In the Metro Vancouver region, several disposal facilities accept butterfly bush plants and/or infested soil (see Resource links below)

Resources

Best Management Practices for Butterfly Bush in the Metro Vancouver Region - June 2023

Butterfly Bush Fact Sheet - July 2023

Invasive Species Disposal Options for Practitioners and their Customers

Regional Brochure - highlighting 12 priority invasive plant species in Metro Vancouver

Photo Credit (in the order they appear on the page): ISCMV; ISCMV; ISCMV; ISCMV; ISCMV; City of Surrey; ISCMV; ISCMV; ISCMV

Habitat

• Prefer permanent, warm, shallow, ponds and lakes with thick vegetation
• Also found in ditches and slow-moving streams, but prefer standing water
• Adapted to human-disturbed habitats and may take up residence in backyard ponds 
• Can tolerate freshwater to brackish habitats 

Impacts

Health & Safety

• May carry the ranavirus and the chytrid fungus that negatively affects frogs around the world

Ecological

• Most of British Columbia’s native frogs are easily consumed by bullfrogs
• There is evidence that bullfrog colonisations of wetlands are followed by declines in species at risk such as the Northern Red-legged Frog and Oregon Spotted Frog 
• Have also been blamed for the decline of snakes and other amphibians 

Social & Economic

• Bullfrog tadpoles can alter ecosystems by changing the structure and composition of algal communities
• Water supply infrastructure damage may occur if bullfrogs invade these areas 

Control Methods

Manual/Mechanical

• Remove egg masses using a fine net or bilge pump every 2-3 days
• Dip nets allow the scooping of bullfrogs near the water’s surface
• Hand capture adults by shining a bright flashlight beam on the surface of the water and slowly capture by hand, net or bucket
• Use a paddle whapper to strike and stun frogs to render them unconscious
• Use an electro-fisher or an electro-froger
• Pellet rifle of at least a 22-caliber is needed to be lethal

Cultural

• Land owners with ponds can create a more attractive environment for native frog species to live in
• Water level management to create temporary or ephemeral pools can limit bullfrog breeding and tadpole survival
• Containment of bullfrogs can intercept access to new locations
• Human consumption of bullfrogs will eliminate some individuals from the environment, but it is not a viable management solution at the landscape level

Resources

American Bullfrog Best Managment Practices - Aug 2021

American Bullfrog Fact Sheet - July 2023

Photo Credit (in the order they appear on the page): Aleesha Switzer; Kendra Morgan; Aleesha Switzer; Micah McDaniel, ABAC & UGA, Bugwood.org; Russ Ottens, University of Georgia, Bugwood.org; Aleesha Switzer; Aleesha Switzer; Aleesha Switzer; M. McDaniel

Habitat

• The European chafer beetle is currently found throughout Vancouver, Burnaby, Coquitlam, Port Coquitlam, Richmond, Delta, Port Moody, District and City of North Vancouver, West Vancouver, Surrey and Maple Ridge
• They have yet to be discovered in agricultural or natural areas in BC, but have been known to live off crop roots in other parts of the world
• The European chafer beetle can be found in lawns and turf along boulevards  

Impacts

Ecological

• Larvae eat fibrous grass roots, which damages the grass plant
• Grubs have a strong scent, which attracts birds and medium-sized mammals (e.g., crows, skunks, racoons, etc.)
• Pedators tear up lawns to consume grubs

Social & Economic

• Damage lawns, sports fields, golf courses and boulevards as the beetle grubs primarily feed on grass roots
• If grubs are numerous and food is scarce, they may move on to planted crops, including corn, potatoes, blueberries, strawberries, conifers, and other crop roots
• Can also cause damage to ornamental and nursery plants by reducing their root system

Control Methods

Biological

• Allow birds and animals to feed on the grubs during the spring
• Every year in July apply parasitic nematodes (microscopic worms that destroy the grubs)

Cultural

• Maintaining a healthy lawn with thick roots and long grass stems or alter the composition of the lawn from turfgrass to an alternate species
• Water your lawn only one hour a week
• Maintain grass height of at least 6cm in height

Resources

European Chafer Beetle Best Management Practices - Aug 2021

European Chafer Beetle Fact Sheet - Aug 2021

Photo Credit (in order of image appearance): Michael Reding, USDA Agricultural Research Service, Bugwood.org; Bruce Watt, University of Maine, Bugwood.org; Bruce Watt, University of Maine, Bugwood.org; UBC Botanical Garden; Ohio State University; ISCMV