Screw you Strangling Dog Vine (European Swallow Wart)

Dog-strangling vine (Vincetoxicum rossicum) is one of the most problematic  invasive plants in Ontario, spreading quickly through ravines, meadows, and parkland. Introduced from Europe, it grows aggressively, forming dense mats that twist and climb over shrubs and trees, blocking light and crowding out all other plants including of course, those that are native.  Once established, it is difficult to remove, as it spreads both by wind-borne seeds and resilient root systems. If you see that you have DSV growing in your yard, please be sure to remove it yourself using gloves, and before the seed pods burst but preferrably up recogition.  Alternatively, have someone remove it for you.

This invasive vine is harmful to all other vegitation but it is uniquely harmful to monarch butterflies.  Monarchs often mistake dog-strangling vine for milkweed and lay their eggs on it, but the caterpillars cannot survive on the plant. Beyond monarchs, the loss of native vegetation affects many insects, birds, and pollinators that rely on diverse native plant communities. When one invasive species dominates, overall biodiversity declines.

The impacts also reach below the surface. By displacing native plants with deep, stabilizing root systems, dog-strangling vine degrades soil structure and disrupts healthy soil biology. Poor plant diversity leads to reduced soil nutrients, weakened microbial communities, and lower overall soil quality, making it harder for native ecosystems to recover.

Toronto Nature Stewards are actively addressing this issue by educating nearby residents on how to identify dog-strangling vine and understand why it matters. Through community outreach and hands-on stewardship events, volunteers help remove the vine from parkland and prevent further spread, while encouraging the return of native plants. This work supports not just monarch butterflies, but healthier soil, stronger plant communities, and more resilient urban ecosystems overall.