An invasive species is a plant, insect or animal that causes damage to the environment, economy or human health in a new region where it is not native. They out-compete native plants for space, food or other resources. Invasive plant species can be difficult to control due to their natural aggressiveness, high rate of reproduction and lack of natural predators in the environment.

• Learn to identify these species
• Use designated trails and keep pets on a leash to avoid accidentally spreading of these invaders
• Learn to effectively and environmentally manage these invasive species on your private property
• Buy native species to plant in gardens and landscaping
• Clean all equipment thoroughly to remove seeds, leaves and mud
• Encourage people to report any illegal importing, distribution or sale of Dog-strangling vine and Japanese Knotweed

For more information on how to deal with invasive species please visit Ontario's Invading Species Awareness Program Website.

The Emerald Ash Borer, is an invasive insect that kills all types of healthy ash trees. It is a major threat to the health of our Region's forests.

The insect was discovered in York Region in 2008 and the City of Toronto a year earlier. While the Emerald Ash Borer poses no risk to human health, it is a significant threat to our forests.

York Region is working co-operatively with the Canadian Food Inspection Agency, the Ministry of Natural Resources, conservation authorities and local municipalities to monitor the spread of this invasive insect and determine the best course of action to help manage its impact.

Visit York Region's website to learn more or, visit the Canadian Food Inspection Agency or call 1-866-463-6017.

The European fire ant (Myrmica rubra Linnaeus), is an invasive, non-native species that is a nuisance pest for people and potential threat to native species. Over the past 10 years, they have been found in residential and natural areas in the Greater Toronto Area. They nest in damp soils around tree roots and under rocks, logs and rotting debris. These ants sting humans, pets and wildlife to defend their nest.

Controlling fire ant colonies on public property

There are no known effective, long-term control methods available for parkland. Known treatments will kill beneficial insects too, which can negatively affect wildlife and the natural food chain.

When travelling through parklands, you're advised to:

• Stay on designated pathways and trails
• Always wear covered footwear and long pants to protect yourself from ant stings and other hazards - different insect bites or poison ivy
• Keep dogs leashed and on the designated trail

Controlling fire ant colonies on private property

Keep your property clean to avoid a potential European fire ant habitat:

• Disposing of yard waste properly. Do not dump yard waste into natural areas
• Keep the area immediately adjacent to your property clear of accumulated branches or decaying vegetation
• Mowing tall grass and trimming hedge
• Avoid transporting materials (soil, mulch, plants, and decaying logs) unless you are certain that it is free of fire ants

Treatment of fire ant colonies

Try using boric acid bait traps, diatomaceous earth, or pyrethrin (these products can be purchased from local nurseries and hardware stores and should be applied according to product instructions). Or contact a pest control company.

If you discover an infestation of European fire ants on your property, treat the colonies quickly to reduce their opportunity to expand into neighbouring areas.

Invasive Phragmites is an invasive plant causing damage to Ontario's biodiversity, wetlands and beaches. It is a perennial grass that has been damaging ecosystems in Ontario for decades. It is not clear how it was transported to North America from its native home in Eurasia.

Origin: The plant is from Eurasia and was introduced to North America in the late 1800s.

Impacts: Phragmites tend to become the dominant species in a variety of habitats, because of its dense growth both above and below ground and its ability to release toxins from its roots into the soil to stop the growth of and kill surrounding plants.

Japanese knotweed is an aggressive semi-woody perennial plant that is native to eastern Asia. It has broad leaves and a vigorous root system. This invader is very persistent and once it becomes established, is incredibly difficult to control.

Impacts: Commonly invades disturbed areas with high light, such as roadsides and stream banks. Reproduction occurs both vegetative (rhizomes) and seeds, making this plant extremely hard to eradicate.

The name “Dog-strangling Vine” refers to two invasive plants native to Eurasia – black swallowwort and pale swallowwort. This invasive perennial prefers open sunny areas, but can grow well in light shade. It grows aggressively up to two metres high by wrapping itself around trees and other plants, or trailing along the ground. Dense patches of the vine can “strangle” plants and small trees.

Impacts: Forms dense stands that overwhelm and crowd out native plants and young trees, preventing forest regeneration. This is a serious concern for the conifer plantations in the York Regional Forest. Leaves and roots may be toxic to livestock. Deer avoid dog strangling vine, which can increase grazing pressure on more palatable native plants. Threats to monarch butterfly populations; butterflies lay their eggs on the plant but, the larvae are unable to successfully complete their life cycle.

Garlic mustard is an invasive herb native to Europe and was brought to North America in the early 1800s for use as an edible herb. It has a strong smell similar to garlic and since its arrival in North America it has escaped into the wild and is now one of Ontario’s most aggressive forest invaders.

Garlic mustard seeds are easily spread by people and animals. They can remain in the soil for up to 30 years and still be able to sprout. The plant can grow in a wide range of sunny and fully shaded habitats, including undisturbed forest, forest edges, riverbanks and roadsides. 

Garlic mustard can invade relatively undisturbed forests. Once established, it can displace native wildflowers like Trilliums and Trout Lily and hinders other plants by interfering with the growth of fungi that bring nutrients to the roots of the plants.

Garlic Mustard can be found in residential yards and gardens. The plant can be easily pulled out of the ground in the spring while soils are moist in late April/May and the plant will flower at the end of April/May making it very identifiable by the flowers for removal. 

Once removed it should be disposed of in your garbage and not with your yard waste.

The plant threatens several of Ontario’s species at risk. The Ontario Invasive Plan Council has some great tips on how to manage Garlic Mustard on your property.

The above information was provided from the Ontario Invasive Plant Council and Ontario's Invading Species Awareness Program. 

A harmful weed that produces clusters of three leaves, it can be found along trails and wooded areas. When the sap from this plant comes in contact with the skin, it produces blisters and irritation.

Wild Parsnip is often found in ditches, trails, and residential properties. When the sap from this plant comes in contact with human skin then is exposed to sunlight it causes severe burns and blisters.

Giant Hogweed is found alongside roads, streams and in open spaces. The sap from this plant can cause severe blisters, burns, and scars. The effects of this plant are further intensified when exposed to sunlight. Eye contact may cause loss of vision.

For more information on how to deal with invasive species please visit Ontario's Invading Species Awareness Program Website.