The District has identified three key invasive plant species that are having a serious effect on Muskoka's environment. These include Invasive Phragmites (Phragmites australis subsp. australis), Japanese Knotweed (Fallopia japonica) and Giant Hogweed (Heracleum mantegazzianum).
Plants species, like the ones listed above, become a concern when they are introduced, either accidentally or purposefully, to an area they aren’t naturally found in. Because they typically are able to reproduce rapidly, thrive in disturbed areas, are highly adaptable and have few natural predators, they are able to out-compete native species for habitat and resources and thus become invasive. Their introduction and spread to an area like Muskoka threatens local ecosystems, the economy and, in the case of Giant Hogweed, our health.
Invasive species are extremely difficult to eradicate once established and their ecological effects are often irreversible as they can alter entire habitats and/or food webs, decrease biodiversity, and threaten species at risk.
Our overall goal is to stop the spread of invasive species and eradicate existing problem species before they become well established in Muskoka.
Learn more about these invasive species below.
(Phragmites australis subsp. australis)
Identifying Invasive Phragmites |
One factor making the identification of invasive Phragmites difficult is the existence of a closely related native subspecies. A number of characteristics of the plant can be useful in distinguishing between the native variety and invasive Phragmites. Invasive Phragmites:
Native Phragmites:
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Impacts of Invasive Phragmites |
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What Can You Do? |
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Managing Invasive Phragmites on Private Property |
Invasive Plant Species cannot be collected at the curb, due to the possibility of seed spread during transportation. Any mature invasive plants with seeds should be carefully bagged in a sealed household sized garbage bag and loaded into your vehicle (covered with a tarp or canopy), and disposed of at the Rosewarne Landfill in Bracebridge. We cannot accept these materials at Transfer Stations, as the seeds could become airborne and spread throughout our area. They must be delivered to their final destination at Muskoka's operating Landfill (Bracebridge). Be sure to inform the Guard upon entering that you have invasive plants (and not simply yard waste), to ensure that your Invasive Weeds are disposed of in the proper location. |
Report a Sighting |
If you find invasive phragmites or other invasive species in the wild, please contact the Invading Species Hotline at 1-800-563-7711, or report a sighting online. |
Helpful Resources and Downloads |
Download the Invasive Phragmites ID Card from Muskoka Watershed Phragmites Fact Sheet (300.6 Kb) Grow Me Instead (11.9Mb) |
(Fallopia japonica)
Identifying Japanese Knotweed |
The stalks grow straight up and can reach as high as 3 metres. The stems appear to be round and reddish-purple in colour. Large, heart-shaped leaves form in a zigzag pattern along the hollow stem. Flowers are cream-coloured that grow vertically from the stem in clusters. |
Impacts of Japanese Knotweed |
Japanese knotweed has a strong root system and can spread about 10 metres from the parent stem and has the ability to grow through concrete and asphalt. This fast growing invasive species is known to change river flows, interrupting spawning beds, it rips through roadways and even threatens foundations of homes. Knotweed commonly grows in gardens, along roadsides and near old buildings or former building sites, according to Ontario's Invading Species Awareness Program.Some studies suggest the plant has extended its range by climate change. While knotweed stems are known to survive temperatures as low as -35C, Canadian frigid winters could be the country's saving grace as the cold will slow down the growth. |
Managing Japanese Knotweed on Private Property |
Unfortunately, getting rid of this plant is very difficult. While digging and cutting knotweed is a solution, this method can break up the rhizomes, creating more growing ends. To control the spread of Japanese knotweed in gardens and residential properties, stems must be cut down several times throughout the growing season to deplete the root system. Cut the base of the stalk just before flowering once the plant reaches a height of 5 to 6 feet. This usually occurs around mid to late June in Muskoka. Subsequent cuttings may occur around early August and again in early September. Persistent cutting may be combined with other options such as digging out roots and laying down tarp material for several years in order to successfully control this species.
Invasive Plant Species cannot be collected at the curb, due to the possibility of seed spread during transportation. |
Report a Sighting |
If you find invasive Japanese Knotweed or other invasive species in the wild, please contact the Invading Species Hotline at 1-800-563-7711, or report a sighting online. |
Helpful Resources |
Grow Me Instead (11.9Mb) Japanese Knotweed Fact Sheet (2Mb) Ontario's Invading Species Awareness Program Website |
(Heracleum mantegazzianum)
What is Giant Hogweed? |
Giant Hogweed, (Heracleum Mantegazzianum), is an invasive plant known for its enormous size. Giant Hogweed has two major negative impacts. Firstly, due to its invasive nature, it poses a threat to native biodiversity. Secondly, Giant Hogweed is a public health hazard. It produces a noxious sap that sensitizes the skin to ultraviolet light. This is known as photosensitivity, which can result in severe and painful burning and blistering. It is important to avoid any skin contact with this plant.
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Where is Giant Hogweed Found? |
It can be found along:
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Is Giant Hogweed a Risk to Human Health? |
Yes.
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Are There Other Plants That Look Like Giant Hogweed? |
Yes.
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Managing Giant Hogweed on Private Property |
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Report a Sighting |
If you find invasive Giant Hogweed or other invasive species in the wild, please contact the Invading Species Hotline at 1-800-563-7711, or report a sighting online. |
Helpful Resources |
Giant Hogweed Fact Sheet (1Mb) |
You can help prevent the spread of unwanted invasive plant species by identifying and reporting sightings in Muskoka by visiting https://www.eddmaps.org/ontario/.