What kind of plant is this? Invasive Dog Strangling Vine alert !


I see these all over a park I frequent around Kennedy/Eglinton. Anyone know what it’s called? It’s a bit wilted now, but they are very straight and stiff when out in the wild.


Thank you for writing and posting this image: what you have taken home and potted is surely a prime example of Dog Strangling Vine (DSV), named as one of the 6 most invasive species of plants by, but not limited to, the City of Toronto, and the province of Ontario.

Identifiable by deep green, oval, smooth-edged, leaves, with a point, and arranged oppositely along the plant stem, this alien member of the milkweed family, Vincetoxicum nigrum, is a prolific producer of rhizome rootstocks and air-borne seeds. The plant you have potted is right now growing upright, but as soon as it can’t hold its weight, will start twining around, and suffocating whatever is nearest at hand.

The definition of ‘invasive’, horticulture-wise,  includes characteristic unbridled growth (as you said, ‘all over’) that typically threatens native plant species. Of related concern: the DSV subverts our native milkweed host plants, the key food source for the already endangered monarch butterflies. The Nature Conservancy of Canada says , ” The monarch, a species at risk in Canada, lays its eggs exclusively on some native milkweed species. These are the only plants that monarch caterpillars have evolved to eat. Some monarchs have been observed laying their eggs on dog-strangling vine plants. Monarch caterpillars hatched on dog-strangling vine plants die because they don’t have the food they need.”

The Toronto Botanical Garden has posted a public-alert, instructional video, on how to properly remove (cut, do not pull) dog strangling vine from its root system, a method which requires vigilant, repeated removal:

TBG on Dog Strangling Vine

Please also visit the City of Toronto’s site for further advice:

City of Toronto invasive specie

And most importantly, the fact that you discovered this proliferating plant in your neighbourhood park, then took a specimen home, and rightly questioned what it is,  is good vigilance on your part. You can also be proactive by reporting your sighting to the Ontario Invading Species Awareness Program.  For everyone reading this, a mobile App is available for tracking and reporting invasive species sightings.

You can also easily  Contact the Invading Species Hotline 1-800-563-7711

Ontario Invading Species Awareness

And finally, when you dispose of  the DSV in your pot, do not put the debris in your compost, or garden waste, but into the garbage, where its tenacious roots will not contaminate.

Again, thank you for your question, and photo!