By Cathy Krar, Master Gardener, SCMG
Dog Strangling Vine, (DSV), tops my list for most “unwanted invasive species”. Having spent hours and hours this past year cutting seed pods, digging out root systems and mowing DSV plants on private properties and hiking trails, I am convinced that this invader is big trouble. It is not particular about habitat. DSV can be found in fields, shrub thickets, on lake coastlines, stream banks, from tall bluffs to deep ravines, from deep shade forest to open prairie.
What is the fuss all about you may ask? Well, perhaps the most well known threat that DSV poses is to our at risk Monarch butterfly population. DSV mimics native milkweed and confuses our Monarchs so that that they mistakenly lay they eggs on DSV. The butterfly larvae starve to death because DSV does not provide the nourishment they need. And if that wasn’t enough to be concerned about, DSV outcompetes our native plants for sunlight, space, water and nutrients. The third weapon in the arsenal is that this invasive, releases chemicals through its roots which inhibit the growth of plants around it. Dense growth of DSV suppresses our native tree seedlings and woodland groundcover plants so heavily that it adversely affects forest regeneration.
If you find DSV growing on your property, rapid removal is the best course of action. If you come upon a large area affected by DSV make a joint effort with your neighbours to control the spread of this invasive. And report your finding to www. ontarioinvasiveplants.ca or by calling the hotline at 1-800-563-7711
The best way to tackle a patch of DSV is by digging out the roots and then disposing of in black plastic bags to cook for up to 3 weeks in direct sunlight. Do not compost or mulch this plant! Even the smallest root fragments can regrow so it is a good idea to keep the site under surveillance for as long as three years to ensure eradication efforts are successful. If the site is too big to dig out entirely then mowing after the flowers have bloomed and before the plant produces seed will reduce the spread of the noxious plant. If you find large areas of DSV in open fields then tarping the area with dark material to block sunlight will cook the root system. Leave the tarp for the entire growing season for highest success. At the very least, a concentrated effort of seed pod removal in mid August- September will also stop further spread of DSV. Whatever you do, do not try tilling the plants in as this will just encourage new root growth.
Next time you’re out on a hike, keep an eye out for this aggressive bully and Monarch butterfly enemy and do what you can to eliminate it from our public trail systems.
