Cottage Q&A
QUESTIONI'm looking for a way to get rid of poison ivy on an area of my cottage property that's close to the shoreline. Can you suggest an environmentally friendly solution? I don't want any harmful chemicals to end up in the lake, but I also don?t want to get a rash every time I go for a swim.
ANSWER
Poison ivy is so toxic, and so pernicious once established, that you shouldn't try burning it, or cutting, pulling, or digging it out. You'd almost certainly come into contact with the plant's toxins, risking a severe reaction.
Though it may seem counterintuitive, in this case the environmentally friendly solution is the effective herbicide Roundup. Its active ingredient, glyphosate, is death on plants, but binds irreversibly with soil and doesn't move anywhere else, including into the lake.
"Around a lake, I'd be more concerned about the wetting agents that keep the glyphosate in solution," says Chris Hall, professor of herbicide physiology and biochemistry at the University of Guelph. "But even these formulants, if applied carefully, directly onto the plants, shouldn't pose a problem to the environment."
Roundup works by moving through the plant along with the products of photosynthesis - so it works best when the plant is most active. If your patch is farther away from the water than three metres, Hall suggests spraying as the simplest solution. Always wait for a still day to spray, and adjust your sprayer to a coarse setting (rather than a fine mist) so the herbicide will drop directly onto the leaves instead of blowing away. Spray first in late spring when the poison ivy is well up, but still small and actively growing. At that time of year you'll kill the tops and might - if you're lucky - get the roots too. Then observe the area over the summer, and if new suckers come up, wait until August (when the plants will be transporting sucrose to their roots for storage) and spray again.
If the poison ivy is closer to the water than three metres, there will likely be some spray drift no matter how carefully you use the sprayer. Here's a technique to avoid getting chemicals into the lake: Using a sponge on a stick, carefully brush a solution of Roundup onto the leaves of each individual plant. At this point you'll be right in amongst the patch, so cover up care-fully. Wear high rubber boots or hip waders, and long rubber gloves. And when the job is done, diligently wash off everything (using detergent and lots of water) that has come into contact with the poison ivy.
* Published in the April/May 2005 issue of Cottage Life
