by Barry Cottam │ Tuesday Invasive Species Group leader at FWG
2012 weekend weed bee half-day events –> Sundays: 8 & 15 July, 12 Aug, 9 Sep from 8:30AM until 12:30PM
Meet at the Interpretation Centre (Building 138); Find us with Google Maps
The Fletcher Wildlife Garden, our Hidden Gem, has been virtually taken over by Dog-strangling Vine (DSV). If you don’t know what it looks like, then you will see acres of lovely green here at the FWG. But if you can recognize DSV, you will immediately realize how much of a problem it has become. First noticed in 1991, around the time the FWG was started, DSV has spread until it is now out of control. Serious, long-term measures are required to put a dent in the population of this highly invasive plant.
DSV is an impressive foe. It grows anywhere, although it does prefer lots of light and soil that has been disturbed. It self-pollinates, so does not need any help from the bees, and its seeds are long-lasting and capable of producing several plants each. And this year the weather has been exceptionally good for it! It grows back readily, whether cut or pulled, our two major control techniques. The crowns of DSV plants hide a number of buds just below the surface, ready to sprout if the main vine is pulled or cut down. As well, removing thick growth allows more light to reach the surface of the soil, stimulating dormant seeds into action.
So why bother trying to control DSV at all? Isn’t it a futile waste of time? Many think so, but we don’t, for several reasons. If we continue our efforts over time, DSV plants that have repeatedly sent out new shoots will weaken; seeds in the ground will eventually be reduced in number; millions of potential seeds will have been destroyed. As well, other species will have more room to move in, restoring some measure of the biodiversity thwarted by DSV. Some species, such as goldenrod and raspberry, compete quite effectively against DSV. We are also noticing that sweet clover can take over DSV sites and keep it under control. Areas that have been cut repeatedly tend to show more variety of species with smaller and weaker DSV plants among them.
TISG volunteers have added to our knowledge by making important observations about DSV behaviour, like that it will twine around itself if no other plants are near (as we’ve never observed any pollinators, we assume that DSV is self-pollinating) or if growing in amidst Rough Goldenrod (rather than growing around the stems of the goldenrod). We have several areas where DSV seems to be losing ground for no evident reason. We’ve hypothesised that walnuts (and their allelopathic juglones) may once have stood in those locations, but that doesn’t account for all of them. A volunteer also found a DSV plant that some insect had been chewing on, so we’re hoping to identify what the muncher was this season.
So there are good reasons to put in the effort! You are very welcome to join us Tuesday mornings from 9 until noon when the Tuesday Invasive Species Group meets, or to join us in one of our weekend work bee half-day events (8 & 15 July, 12 Aug, 9 Sep from 8:30AM until 12:30PM). In addition, the work bees provide outdoor exercise and a chance to socialize with others with whom you have something in common – a distaste for DSV and a desire to help us save the FWG!