The invasive species in Ontario crowd out the native species. The spread of these species poses a risk to society, the economy, and human health.
For instance, invasive plants in Ontario compete with native plants for sunlight, soil nutrients, and water. As a result, the native plants struggle to grow.
Furthermore, such species can change the soil chemistry. This alteration of diversity may lead to the reduction of biodiversity.
Both human and environmental factors play a role in the seed dispersal of these Ontario invasive species. Therefore, if you have a lush garden, you need to be careful.
So, without further delay, let’s discuss the names.
Learn More: Rain Garden: Transforming Your Outdoor Space
11 Invasive Plants Ontario: The Most Dangerous Invasive Species in Ontario
Here is a list of invasive species in Ontario that you need to prevent:
1. Giant Hogweed
The huge, white, umbrella-shaped flower clusters of giant hogweed, one of the invasive species in Ontario, usually reach a height of three to five meters in mid-June.
It may frequently be found in fields, open forests, ditches, riverbanks, roadsides, and even city parks.
Like many other invasive plants in Ontario, giant hogweed may grow into dense clumps, outcompeting native plants.
With its photoreactive sap that blisters and severely burns flesh when exposed to sunlight, it poses a risk to public health as well. In some cases of sap exposure, the afflicted people had to be hospitalized due to the severity of the blisters.
Herbicide spraying, digging, mowing, cutting, removing umbels, and grazing are common methods for controlling giant hogweed.
The control strategy you use will be influenced by the population density, accessibility, and area covered by the population.
Given that gigantic hogweed produces a good amount of seeds, it is highly advantageous to maintain ongoing care to stop seed production.
The majority of experts suggest that eradicating it will take five years of rigorous treatment.
Mechanical or cultural control stops the plant from producing seeds by exhausting its root system’s energy reserves.
The most widely used method of control is chemical control. Herbicides can efficiently reduce gigantic hogweed.
You need to apply the herbicides a couple of times for them to work efficiently.
To learn the organic methods of eradicating weeds, here is a blog.
2. Wild Parsnip
Another one of the invasive plants in Ontario is wild parsnip. Even though the roots of wild parsnips are edible, the plant’s sap can burn you severely.
Poison parsnip, another name for wild parsnip, belongs to the parsley/carrot family.
Usually, during the first year, while the root is developing, these invasive species in Ontario produce a low, spindly rosette of leaves.
In the second year, these invasive species in Ontario grow flowers on a long stalk before dying.
3. Dog Strangling Vine
European swallow-wort belongs to the milkweed family and is often referred to as a dog-strangling vine.
This is one of the most common invasive vines in Ontario. Although it is not really dangerous to dogs, it does put native species and their ecosystems at serious risk.
It spreads rapidly, and it is found in several areas of southern Ontario. Its widely dispersed seeds are tiny and fly long distances when distributed by the wind.
To recognize these invasive species in Ontario, pay attention to their leaves. DSV leaves are oval in shape and oriented oppositely on the plant stem.
Different varieties of these vines differ in size and color, and their appearance will be so different from that of native plants that you will identify them instantly.
4. European Buckthorn
Common or European buckthorns are the types of invasive species in Ontario that thrive in many different habitats, mostly in open fields and woodlands, all over southern Ontario and other regions of Canada, such as Manitoba.
These have the ability to change the soil’s nitrogen levels, which inhibits the growth of native species.
To be specific, these are the deciduous types of invasive shrubs in Ontario. That means they will lose their leaves in late fall and because it leaves early in the spring.
To find them, look for an orange inner bark and a dark outer bark filled with tiny pores, it can reach a height of two to six meters. There is a waxy coating on the twigs, and some of them have noticeable, sharp thorns.
In August and September, the toxic black berries will appear that will stay on the stem throughout the cold season.
5. Autumn Olive
Elaeagnus umbellata, or autumn olive, is again a deciduous shrub.
The plant’s fast and uncontrollably spreading nature may result in the replacement of native plants in meadows, roadsides, forests, and grasslands. Even though previously, these invasive species in Ontario were believed to be useful with erosion management, people have now realized there is more bad than good about them.
Autumn olive can reach heights of 20 feet and widths of 30 feet.
Early spring is when Autumn Olive’s bell-shaped blossoms, which are a cream or pale yellow tint, bloom. They produce red berries with silvery dots.
These invasive species in Ontario displace native species by altering the surrounding soil’s chemistry. This process is known as allelopathy, which is a term that indicates the effects on the growth of plant species.
One of the main causes of a decline in biodiversity is invasive species, and the loss of native vegetation can have a cascade impact on an ecosystem.
6. Garlic Mustard
These are currently one of the most hostile invasive species in Ontario.
In the first two years of life, garlic mustard plants have two unique life stages. These invasive species in Ontario grow just a rosette-shaped cluster of leaves in the first year as a robust root system is established.
In their second year, winter-hardy plants yield hundreds of seeds and blossoms.
Garlic mustard are the type of invasive plants in Ontario that have a four-year growth cycle.
Both humans and animals can readily disperse garlic mustard seeds. They have the ability to sprout even after being submerged in the earth for up to 30 years.
The plant can be found growing in various sunny and completely shaded environments, such as riverbanks, forest borders, and forests.
Numerous native Ontario plants bear similarities to these invasive plants in Ontario. The leaves at the base of the plant resemble those of numerous plants belonging to the families of daisies, violets, and carrots.
The plant is garlic mustard if it smells strongly of garlic as you crush its leaves.
7. Goutweed
Goutweed is a perennial groundcover native to Eurasia. These invasive weeds in Ontario have other common names like bishop’s weed or snow on the mountain.
You can spot them in some Ontario garden centers.
Goutweed is a low-growing plant with compound leaves that are either green with a white margin or composed of three groups of two to three leaflets.
In late spring and early summer, small white flowers emerge in wide, rounded clusters above the foliage.
Goutweed can also proliferate by seed, which can cause it to spread rapidly.
The invasive plants in Ontario that sprout from seeds have solid green leaves and compete more for their survival.
Learn More: Guide To Understanding & Managing Different Types of Weeds
8. European Frog-Bit
European frog-bit are aquatic plants that have heart-shaped, leathery leaves and tiny, three-petaled white blooms that float around freely. Although the root system is well developed, it typically does not attach these invasive species in Ontario to the substrate.
You may find them placid bodies of water, including ditches, ponds, protected inlets, and slowly flowing rivers.
The decomposition of large frog-bit patches that die in the fall can lower the water’s oxygen content, which can impact aquatic life.
Stem fragments, seeds, and winter buds can all sprout new plants and can transfer to new areas by boats and wildlife.
In shallow water, these invasive species in Ontario can float on their own or erect roots up to 50 cm long.
They yield a single, up to two-centimeter-wide, white flower with three rounded petals and a golden center.
The leaves have a round or heart shape and are 2.5–5 cm wide, and they may create a rosette as wide as 6 cm.
The purple-red leaf bottom floats in the water thanks to a spongy coating that runs along the leaf’s central vein.
9. Erect Hedge Parsley
Invasive plants in Ontario that grow hedge parsley may be annual or biennial. It may just have a rosette of leaves that resemble parsley close to the ground in its first year.
Erect hedge parsley grows well in both open and shaded environments. Its habitat consists of meadows, woodlands, and disturbed places like roadside ditches.
Because it is self-fertile and unspecialized (producing both male and female flowers on the same plant), erect hedge-parsley attracts a wide variety of insects, including wasps, bees, flies, and beetles.
Some people suggest that erect hedge-parsley may change native plant-pollinator interactions. However, there is no evidence to support the statement yet.
10. Flowering Rush
Another invasive species in Ontario called flowering rush looks like a big sedge and has pretty pink blossoms. The typical plants produce an umbrella-shaped cluster of 20 to 50 flowers, which appear from early summer to mid-fall.
The leaves of flowering rush have a triangular cross-section, narrow toward the leaf tip, and can grow up to two meters tall.
These invasive species in Ontario are quite easy to identify when they blossom.
The flowering rush is usually an emergent plant in shallow waterways of wetlands, irrigation canals, lakes, and rivers.
They can also change their growth type in deeper waters (usually three to six meters deep).
In these areas, they appear as submerged plants with flexible, ribbon-like leaves that do not blossom. It needs full light, damp soil, and a wide range of substrate types from sandy to clay and acidic soil.
11. Black Alder
One big type of deciduous tree is black alder. These invasive species in Ontario reach mature heights of up to 50 feet when grown under ideal conditions, with a loosely pyramidal 35-foot-wide crown.
On twigs, leaves are in a sporadic arrangement. The leaves are usually 2–4 inches long and 3–4 inches wide, with an oval to round form with a notched tip.
The foliage remains a deep green, lustrous color into the fall. Young leaves often have a gummy substance that makes them sticky.
Because of its quick growth and high seed production rate, black alder plants form single-species colonies by outcompeting other plants and native trees.
Being a nitrogen-fixing plant, it converts nitrogen from the air into forms that plants can use by bacteria that settle in its roots.
Additionally, this plant generates a lot of leaf litter, which may have an impact on soil acidity and the cycle of carbon.
FAQs
What are invasive species in Ontario?
Non-native organisms that may threaten the environment, the economy, or public health are what we call invasive species. They can be fast-spreading species that replace native ones, such as fungi, animals, plants, or microbes.
Why are invasive species in Ontario a problem?
Invasive species in Ontario disrupt ecosystems, endanger Ontario’s biodiversity, and can have a large financial impact. They may also be harmful to human health and can affect forestry, fishing, and agriculture.
Does Ontario have any public education initiatives about invasive species?
Yes, a number of initiatives spread information about invasive species in Ontario to the general public. These include:
Authorities offer workshops and training sessions under the Ontario Invasive Species Awareness Program (OISAP).
Educational tools and materials are accessible via official websites and institutions such as the Invasive Species Centre.
Contact Our Lawn Care Experts in Mississauga to Get Rid of Invasive Species in Ontario
These were the invasive species in Ontario that you should never underestimate if you find them around your house.
If you do, be sure to contact our lawn care experts in Mississauga to rid of these invasive plants Ontario.