Invader of the Day
May 30 Burdock
Burdock is a tall, invasive herb known for clinging burs that were the inspiration for Velcro. Burdock is a pain, literally, as the burs get tangled in manes and tails of horses, cows and other livestock. Each plant can produce 6,000-16,000 seeds each year so preventing the production of the burred seed is a key way to prevent spread.
May 29 Scotch Broom
Scotch broom is an escaped garden ornamental which invades rangelands, replacing forage plants. It is a serious competitor to conifer seedlings; Douglas fir plantation failures in Oregon and Washington have been credited to infestations of this plant.
What you can do. Be PlantWise. A few native and ornamental alternatives to plant instead of Scotch broom include: Prickly Rose; Shrubby Cinquefoil; Forsythia; Deciduous Yellow Azalea; and Japanese Kerria. Read more about these alternatives in the Grow Me Instead booklet for BC.
May 28 Koi
Koi or Japanese Carp can have a major effect on lakes and rivers, if dumped, wiping out native species and dramatically altering the environment.
What you can do. Don’t let it loose! Never release goldfish or any live fish into lakes, rivers or streams. Return or donate unwanted aquarium fish, reptiles and plants to a pet store, SPCA or local school.
May 27 Flowering Rush
Flowering rush is a beautiful aquatic plant which can be found along shore lines of lakes or rivers. As an invasive species, this plant creates dense stands which can be harmful to native flora and fauna and has caused significant damage in the Great Lakes.
What you can do: Now is the time to help prevent the spread of this plant in BC. Always ‘Clean, Drain, Dry’ boats and equipment before leaving a water body, take extra caution when transferring boat or equipment from one province to another. Be ‘PlantWise’ and choose an alternative non-invasive species when planting a garden.
May 26 Northern Pike
Northern Pike can be found throughout most of British Columbia (BC), this species is known as a commercial and a sport fish and in some areas an invasive species. The territorial nature of this species makes it a dominant predator in the lakes and rivers it inhabits. Typically, the Northern Pike will eat whatever is available; this includes fish, amphibians, mice, and small waterfowl. The diet of the Northern Pike is the reason some areas consider this species an invasive.
What can you do? Although this species is not invasive throughout BC, it is still illegal to transport from one water body to another. If the species has been found in a new location please report it to your local DFO office.
May 25 Largemouth Bass
The Largemouth Bass is native fish species to eastern North America; this is an invasive species that inhabits lakes and rivers throughout British Columbia. This fish is to blame for declines and local extinctions of several small prey fish. Largemouth Bass is capable of carrying hundreds or parasites and 4 of these parasites have been found on Largemouth Bass in BC (DFO).
What can you do? Do not transport this species into other water bodies around BC. Assure that you properly Clean, Drain, Dry your boat before entering a new water body, you never know where these fish could hide! If the species has been found in a new location please report it to your local DFO office.
May 24 Purple Loosestrife
Purple Loosestrife is an invasive wetland perennial common throughout most regions of British Columbia (BC) and is currently listed as a regionally noxious weed under the BC Weed Control Act. This woody shrub lacks in nutritional value and continues to dominate native and endangered wetland plant species. Purple Loosestrife does not offer cover or nesting materials; because of this many animal species have left areas it inhabits.
What can you do? Instead of using Purple Loosestrife as an ornamental plant on your property, please be PlantWise and use one of the several alternative non-invasive species in its place. Please report any sightings of this species to your local regional invasive species committee.
May 23 Zebra & Quagga Mussels
Zebra and quagga mussels are small freshwater mollusk species introduced to North America from Europe. due to their ability to easily attach themselves to objects or other organisms. These species are difficult to remove and have been found clogging water treatment and power plant pipes. Both Zebra and Quagga Mussels have negatively impacted native flora and fauna and continue to spread through Canada.
What can you do? These species are currently not found within British Columbia , this is an alert species and prevention is very important. All anglers and boaters transferring boats into BC from other provinces must assure they have properly Cleaned, Drained, and Dried their boat. Report any sightings of these species to the Report All Poachers and Polluters program.
May 22 Eurasian Watermilfoil
Eurasian watermilfoil is an invasive aquatic perennial first seen in the Okanagan in the 1970’s, and has since spread to lakes throughout the Okanagan Valley, Kootenays and Lower Mainland. The plant forms thick vegetation mats that limit boating, swimming, and fishing, displace native plant species and decrease biodiversity and water quality. Boats and boat trailers carrying plant fragments are the most common form of spread between water bodies.
What can you do? Always Clean, Drain, Dry your boat, trailer and fishing gear when leaving a water body, and dispose of any plant material far away from water bodies. Learn how to identify Eurasian watermilfoil and report any new infestations to your local regional invasive species committee.
May 21 European Rabbit
The European Rabbit can be found on Vancouver Island and regions within the Lower Mainland of British Columbia (BC). This is a common species that one could purchase in a pet store, however due to its introduction into the wild it has now established and has become an invasive species (E-Fauna BC). These rabbits consume a large amount of vegetation per day; this diet has led to negative impacts on gardens and agriculture in the regions it inhabits.
What can you do? Do not feed or transport the European Rabbit. Fences and wire can be installed around your property to prevent the rabbit from damaging your garden. Report any sightings of this rabbit in new regions to the Report All Poachers and Polluters program.
May 20 Eastern Grey Squirrel
Although cute, the Eastern Grey squirrel is considered an invasive mammal species within British Columbia (BC). Native to central and eastern North America, this species can now be found in the Lower Mainland, Vancouver Island, and southern interior regions of BC. This introduced species has led to the decline of the native Red squirrel due to competition for food and habitat. The Grey squirrel can be either grey or black in colour, and is twice the size of the native Red squirrel. These squirrels also cause problems by digging up lawns, eating garden bulbs, removing roof shingles and shakes, and chewing through eaves to nest in attics, roofs and chimneys.
What can you do? Do not feed or relocate the Eastern Grey Squirrel. Keep all compost, garbage, and pet food properly stored and covered. When placing bird feeders on your property, make sure you use squirrel-proof feeders.
May 19 Emerald Ash Borer
The Emerald Ash Borer is a species of beetle native to Asia, since the first North American sighting in 2002; this beetle has been destroying the native ash populations within eastern Canada. Few natural predators have led to the success of this species and limited resistance has led to the decline of native ash trees. Research suggests after 6 years in a stand, the Emerald Ash Borer will have killed 99% of the trees (NR Canada).
What can you do? Report any sightings of the Emerald Ash Borer to the Canadian Food Inspection Agency.
May 18 Canada Thistle
Canada Thistle is a common invasive weed found all throughout British Columbia. It typically inhabits disturbed areas such as ditches and cut blocks. Canada Thistle is a provincially noxious weed under the BC Weed Control Act and is known to outcompete native forage species, this competition has led to a decline in yield and productivity of rangelands.
What can you do? Practice PlayCleanGo. When walking through infected areas, assure all seeds are removed from clothing and animals before leaving site, leave all plant materials and infected site. Minimize soil disturbance and revegetate bare soil as soon as possible.
May 17 Gypsy Moths
Gypsy Moths are an invasive insect found throughout southern Canada; they originate from Europe and Asia and since their introduction, have been negatively impacting native tree species. Gypsy Moths will defoliate the hardwood trees which host them and eventually lead to death of the trees. There are several chemical and biological management techniques for this species; however, outbreaks allow the species to continue spreading throughout the country.
What can you do? Identify Gypsy Moth egg masses; these can be controlled on your property by burning or soaking in a water soap mixture. Serval traps can be used on tree trunks to catch caterpillars. Keep trees on your property healthy so they are able to withstand an attack. Contact the Canadian Food Inspection Agency (CFIA) with any sightings of this species.
May 16 Hound's Tongue
Hound’s-Tongue, native to Eurasia, is an invasive noxious weed found within the southern interior of British Columbia. This short lived perennial plant takes over rangelands and grazing pastures reducing amount of available forage for grazing animals. The quickly attaching burrs found on this species not only cause problems for people and animals, it also allows this species to spread further distances.
What can you do? If you have Hound’s-Tongue on your property hand pull the plant before it begins to seed, remove as much roots as possible. If you have recently removed native vegetation on your property, replant as soon as possible. Remove burrs from animals and clothing before leaving the infected area. PlayCleanGo to help prevent its spread.
May 15 Giant Hogweed
Giant hogweed is an invasive perennial species found in the Lower Mainland, Fraser Valley, Gulf Islands, and Vancouver Island regions of British Columbia. The ecology and seed production of this species allows it to outcompete native vegetation and colonize quickly, typically with other aggressive invasive species. The stem hairs and leaves on this species contain a highly toxic sap that can burn, blister or scar if it comes in contact with skin.
What can you do? Instead of using Giant Hogweed as an ornamental plant on your property, please be PlantWise and use one of the several alternative non-invasive species in its place. Please report any sightings of this species to your local regional invasive plant committee.
May 14 Hoary Alyssum
Hoary alyssum is an annual plant in the Mustard family that grows to 0.7 metres tall with white flowers; the whole plant is covered with star-shaped hairs, and the oval seedpods are held close to the stem. If pregnant mares consume hay that is contaminated with hoary alyssum, it can cause a specific condition that leads to foals being born with facial, lower jaw and limb deformities .
What can you do?
Always feed certified weed-free hay - Make sure that hay is free of mustards and keep mares that are late in pregnancy off weedy pastures that contain plants in the Mustard family.
May 13 Leafy Spurge
Leafy spurge is a perennial plant with greenish-yellow flowers and both vertical and horizontal creeping roots. It is considered one of the most unwanted invasive plants in BC - all parts of the plant are toxic, and contain a white milky latex that can irritate the skin of livestock and humans and cause temporary blindness if the sap gets into the eyes. Animals that eat leafy spurge get gastrointestinal irritation , redness and swelling of the mouth and salivation and head shaking.
What can you do? Never plant leafy spurge in your garden – some gardeners have spread this plant around! Refer to this BC government web page for information on prevention and control methods.
May 12 Knotweeds
There are four different species of invasive knotweeds in BC: Japanese, Bohemian, Giant and Himalayan Knotweed. Showy white flowers and heart-shaped leaves have made knotweed a popular horticultural plant, yet it is very invasive, spreading rapidly along water systems and roadways. Knotweeds shade out other plant species, dominating streams and riparian areas and causing soil erosion and loss of fish habitat. Knotweeds are found in southern BC, the Shuswap and Haida Gwaii
What can you do? Do not use knotweed as an ornamental plant on your property; be PlantWise and use one of the several alternative non-invasive species, such as Red-osier dogwood. Please report any sightings of this species to your local regional invasive species committee.
May 11 Hoary Cress
Hoary Cress is a perennial invasive species, commonly found in hayfields or rangelands on the coast and in the interior of British Columbia. This species spreads rapidly using roots and seed dispersal - each plant can produce 4800 seeds - and outcompetes native vegetation and crops. Hoary cress is considered a regionally noxious plant under the BC Weed Control Act as it is unpalatable to livestock yet often found in alfalfa hay.
What can you do? Report any sightings of this species to your regional invasive species committee. If walking or driving through areas where this species is located, check your clothing and equipment for any seeds, and carefully remove all mud and debris from vehicles to help prevent the spread of this species.
May 10 European Fire Ants
The European fire ant is one of the top 100 worst invasive species in the world, and was introduced from Eurasia to eastern North America in the early 1900’s. The ant is named after its painful fire-like sting, and is known to attack once disrupted. It was first confirmed in BC in 2010, has spread throughout the Lower Mainland and southern Vancouver Island, through soil and garden materials. Unlike native ant species, the nests of the European Fire Ants are difficult to spot and hard to eradicate; they prefer humid nesting areas such as under shrubs, tree roots, or rotting wood.
What can you do? When purchasing new plants or gardening supplies, inspect all purchases to make sure there are no ants trying to hitch a ride. Make your property less attractive to European fire ants by reducing areas of exposed soil or yard clutter, especially scattered rock and woody debris. Report any sightings to your regional invasive species committee.
May 9: Hawkweeds
British Columbia has 14 non-native species of hawkweeds, many brought in by gardeners as colourful orange and yellow perennials for their gardens. BC also has eight species of native hawkweeds, but due to their similar appearance, the non-native species are difficult to identify among the native ones. With multiple ways to spread and disperse, hawkweeds form dense mats in fields, displacing hay and other crops, and increasing management costs.
What can you do? Never use hawkweed as an ornamental plant on your property – once established it is very difficult to control. Please be PlantWise and use one of many alternative non-invasive perennials instead, such as Alpine asters. Please report any sightings of this species to your local regional weed committee.
May 8: Yellow Flag Iris
Yellow Flag Iris is a wetland perennial found in BC’s Lower Mainland and the southern interior. Native to Europe and North Africa, its appealing yellow flower and sword-shaped leaves make it a popular species in garden centres and home water gardens. However it is very invasive and threatens aquatic ecosystems due to its ability to spread rapidly, form dense patches and restrict water flow in streams and irrigation ditches. Yellow flag-Iris negatively impacts wetlands, wildlife and outcompetes native plants, yet its popularity makes efforts to contain new infestations difficult.
What can you do? Instead of using Yellow flag-Iris on your property, please be PlantWise (weblink) and use one of the many alternative non-invasive species in its place, such as the Western blue iris. Please report any sightings of this species to your local regional weed committee.
May 7: Brazilian Elodea
Found in fast-moving and still bodies of freshwater, Brazilian elodea (Egeria densa), or “dense waterweed”, is an invasive aquatic plant that has managed to spread from its’ home range in South America to almost every corner of the globe, including southwestern British Columbia. Brazilian elodea resembles native waterweeds with bright green stems and leaves, however is much larger and more robust. Stems grow until they reach the surface where they form dense mats, crowding out and altering the light and nutrients available to all other underwater biota. Their dense, monoculture stands also interfere with recreational activities such as boating and swimming, and even particles can destroy infrastructure; in New Zealand, hydroelectric plants were shut down when pieces of dense waterweed clogged intake structures, with extremely expensive repair costs.
What can you do? Proper prevention and diligent disposal! Brazilian elodea is a popular aquarium plant, usually sold under the name ‘Anacharis’, and is commonly used in botany classrooms and plant research. Its escape into the environment through the dumping of aquarium contents, and the spread between waterbodies via plant fragments attached to boats, boat trailers, and other equipment (even snorkels and fins!) can turn entire lakes into dense mats. By properly disposing of Brazilian elodea, or else using alternatives like Canadian elodea (Elodea canadensis) in aquariums, we can avoid spreading the species further. If boating or swimming in the southwest of the province, be sure to Clean, Drain, and Dry all equipment. Protect our waters - Don’t Let it Loose, and Clean Drain Dry.
May 6: Parrot's Feather
Parrot's Feather is an aquatic plant species native to South America. It is a popular ornamental species for backyard aquatic gardens and ponds because of its feather-like bright green foliage. Parrot’s Feather is now listed as an invasive species within BC and is illegal to purchase in several American states due to its ability to rapidly take over water bodies. Currently, it can be found in Richmond, and is spreading throughout the Lower Mainland of British Columbia.
What can you do? Never dump unwanted pond or aquarium plants into ditches or water sources – dry and freeze them, then bag them for the landfill. Always use the Clean, Drain, Dry procedure when taking your boat out of the water, to reduce the chance of this species spreading. If you spot this species in the wild, please report it to your local invasive species council.
May 5: Goldfish
Goldfish make cute pets but become an aggressive invasive species if discarded into lakes, rivers or streams. Goldfish out-compete native species for food and habitat and spread diseases, as well as spread from one body of water to another. Koi and goldfish can survive our province's climate and can grow to be very large and have no natural predators here.
What you can do. Don’t let it loose! Never release goldfish or any live fish into lakes, rivers or streams. Return or donate unwanted aquarium fish, reptiles, and plants to a pet store, SPCA or local school.
May 4: Round Goby
Native to Eastern Europe, the Round Goby was first sighted in Canada in 1990, and has since successfully spread through all five Great Lakes. The Round Goby has become a threat to many native fish species, including several species that are at risk, as they feed on fish eggs and young fish. This has led to a decline in several sport fish species.
What can you do? Don’t Let It Loose! Never release live fish into any water body. Always use the Clean, Drain, Dry procedure when leaving a water body, to make sure no fish eggs or young are in your boat or equipment. Report any sightings of this species to your local invasive species council.
May 3: Rusty Crayfish
Rusty Crayfish are an aggressive species of crayfish that are native to the Ohio River Basin. They were first sighted in Canada during the 1960’s, and now have now spread over southeastern Ontario. Native flora and fauna have been seriously impacted due to this crayfish; native crayfish species are outcompeted for food and habitat, and native fish species are losing their spawning grounds due to the large amount of aquatic vegetation that the Rusty Crayfish consumes.
What can you do? Learn how to properly identify a Rusty Crayfish. If using this crayfish for live bait they must only be used in waterbodies where they are already located, do not release Rusty Crayfish into other waterbodies. Always use the Clean, Drain, Dry procedure when leaving a water body.
May 2: American Bullfrog
The American Bullfrog is native to eastern North America; it was introduced to British Columbia in the early 1900’s to farm for its meaty legs. Its sheer size makes the American Bullfrog quite distinctive from the native frog and toad species of BC – it can grow up to 20 cm long. It is a highly adapted predator, known to eat anything that will fit in its mouth, including fish, amphibians, small mammals, and native frog species that may be at risk of extinction. Bullfrog tadpoles are often caught by children to raise into frogs, due to their large size, and then moved from pond to pond.
What can you do? Never transfer Bullfrogs or their tadpoles from pond to pond, and don’t let them loose if you raise one! If you find Bullfrogs, please report it to your local invasive species council, or download the "report an invasive species" app to help keep track of the spread of this species throughout BC.
May 1: Red-eared Slider Turtle
The Red-eared Slider is a popular pet species that has been introduced into native ecosystems within southern British Columbia. A distinctive red patch along the sides of their face distinguishes the Red-eared Slider from the native Western Painted Turtle. Some pet owners release this species into the wild when they grow too large or no longer want to care for them. These turtles can thrive in BC’s ponds and lakes, and out-compete native turtles for food, sunning logs and nesting sites. Released pet turtles also spread diseases to wild populations.
What can you do? Don’t Let It Loose! Never release pets into the wild. Before purchasing the Red-eared Slider as a pet, do your research: this species typically lives longer than 20 years and will grow to the size of a dinner plate! Check with the store you purchased it at, to see if they will take it back, or contact a local aquarium or zoo. If you sight a Red-eared Slider in the wild, report it to your local invasive species council, or download the "report an invasive species" app to help keep track of the spread of this species throughout BC.