An invasive weed is a plant that comes from a different place of origin other than Alberta, however, not every introduced plant becomes invasive. Characteristics that make plants invasive are:
- Out compete native plants
- There is no natural enemies or pathogens to keep them in check where the plants were introduced to
- Grow and spread quickly, forming a dense mat of single species (monoculture)
- Infest streams, riverbanks and waterways as well as terrestrial ecosystems
- Reduce biodiversity and disrupt the balance of local ecosystems
The Alberta Weed Control Act defines a list of regulated weeds that need to be controlled or eradicated by property owners. There are 46 prohibited noxious weeds that should be destroyed when found, and 29 noxious weeds that should be controlled and prevented from spreading. The term “noxious weeds” is sometimes used by the media and the public to refer to all the regulated weeds.
The municipalities will prioritize preventative methods of pest management and will support long-term management of pests using a combination of techniques including mechanical and physical treatments, biological control, habitat manipulation, and judicious application of pesticides.
The City of Edmonton has a Herbicide Ban Motion in place to eliminate non-essential use of herbicides on city-owned land. However, there are exemptions that allow for their use. Herbicides are used to:
- Ensure City infrastructure is safe and well-maintained. This includes use on sewer pipes, storm water facilities, concrete surfaces and along LRT routes.
- Maintain cemeteries, bowling greens, premier sports fields, as well as parkland used in high-profile events.
- Manage regulated weeds listed in the Alberta Weed Control Act.
Answer coming soon.
For help identifying weeds, use the Weed Identification lookup tool.
Please note that a weed identification request is not used to make complaints. It will not prompt actions from bylaw officers or operational teams.
A lot of invasive plants were introduced to Canada as ornamental plants because they are beautiful. Sometimes introduced ornamental plants escape from gardens and farms into natural areas, and they are found to be invasive.
Creeping Bellflower is listed as a noxious weed in the Alberta Weed Control Act, and property owners are required to control the spread of it, but eradication is not mandatory. To control it, dig out the plants with as many roots as possible.
As soon as you can get the new growth out of the ground, the less energy can be stored in the roots of the plants. Over time, you will starve out the roots. If you can not get the whole population out, make sure to remove flowers before they produce seeds to stop seeds from going into the soil.
Invasive species can destroy or disrupt natural ecosystems. Invasive species can out-compete native species, when they often have no predators or any other deterrents to establishment or spread. A 2021 study estimated that invasive species have cost North America $2 billion per year in the early 1960s to over $26 billion per year since 2010 (Crystal-Ornela, R. et al. 2021). Globally, it is estimated that the economic cost of invasive species has been $1.288 trillion over the past 50 years (Zenni, R.D. et al. 2021). Rising human populations, increasing international trade and climate change all will be increasing the likelihood of the spread of current invasive species into new areas and the introduction of new problematic species. Simple actions in prevention can reduce significant impacts and costs from eradication and management efforts.
Crystal-Ornelas R., E.J. Hudgins, R.N. Cuthbert, et al. 2021. Economic costs of biological invasions within North America. NeoBiota 67:485-510.
Zenni R.D., F. Essl, E. García-Berthou, et al. 2021. The economic costs of biological invasions around the world. NeoBiota 67:1-9.
Invasive species are hard to address because they hold a series of traits that gives them a competitive advantage. Common invasive species traits include fast growth, rapid reproduction, high dispersal ability, phenotypic plasticity (the ability to alter one’s growth form to suit current conditions), tolerance of a wide range of environmental conditions, ability to live off of a wide range of food types, single parent reproduction (especially in plants), and, commonly, association with humans (Williams and Meffee 1998). Early detection and rapid response is critical to ensure the best chance to minimize impacts and dispersal.
Williams JD, Meffe GJ (1998) Nonindigenous species. In: Mac MJ, Opler PA, Puckett Haecker CE, Doran PD (eds) Status and trends of the nation’s biological resources. US Department of the Interior. US Geological Survey, Reston, VA, p 117–129.
Report the sighting! Make sure to record where you saw the species and, if possible, take photos of the species and the host tree. This will help experts identify the species and evaluate the risk. Follow the information below to find out who to contact:
Humans are the driving force allowing the introduction of potentially invasive species by land, air and water travel. Given known impacts, it is worth the effort to try to minimize impacts as much as possible. Invasive species are among Canada’s greatest environmental threats to the survival of our native species.
Invasive species arrive, often accidentally but sometimes intentionally, and in the absence of natural predators, kill, crowd out or otherwise devastate native species and their ecosystems at an alarming rate.Economic costs of invasive species are dramatically lower when funds are invested in prevention and early detection efforts.
Once an invasive species establishes and spreads, management is exponentially more expensive and less efficient.·People will begin to feel the loss of ecosystem services like flood and climate change resilience, reduced bio diversity, reduced resource production, impact to tourism and recreation activities and reduction in property values.
Contact your local municipality.
Invasive species are species that exist in an area outside of their native or historic range. Therefore, in Canada, an invasive species can come from any other part of the world. Many invasive species in North America are native to our common trade partners, such as Europe and Asia, introduced accidentally through human activity. Europe and Asia also have similar climates to North America, increasing the potential for an introduced pest to become established.
Invasive forest pests can enter Canada through a number of pathways, both natural and human-influenced. Urbanization increases the potential for spread of invasive species, as hitch-hiking insects can follow the movement of people and products from one area to another. Invasive species can also spread through vectors (eg. carried by birds), or natural dispersal outside of their native range.
No. In addition to invasive species, Canada has a number of native forest pests that can be damaging to trees and forests. Some examples of native pests are the forest tent caterpillar and the spruce budworm. Outbreaks of these pests occur regularly across Canada within their historical ranges, and are considered natural disturbances within the ecosystem.
- Report all new sightings
- Don’t move firewood
- Be sure to clean your shoes, bikes, ATVs, and other outdoor equipment thoroughly after a hike or ride through a natural area
- Stay on trails and pathways
- Avoid known infested sites
- Plant native plants and trees
- Properly dispose of garden waste and compost
- Do not move plants, seeds, fruits, woody materials, or other plant parts across borders.
- Do not place bird feeders near hemlock trees