It has been a busy few weeks for me — holiday traveling, Green Expo talks (that’s our regional conference), and getting ready for a semester leave this year — I’ll be working on a project investigating how professors transfer information to the public. But during this time I have, for some unexplainable reason, been thinking about Canadian Thistle. And do you know what I’ve come up with? This:
It’s a colossal waste of time and money to worry about Canadian thistle.
Despite its name Canadian thistle is not native to North America. It was introduced in the 1600s — probably by accident. Most parts of the plant are edible and some people even say that it’s tasty. Though it can be found across the US it is rarely found in such high concentrations that it displaces native species. Where it does dominate the landscape conditions are usually bad enough (highly disturbed sites) that other plants won’t fare well anyway. Canadian thistle is known as an early succession plant which means that it will establish in a disturbed site — perhaps even taking it over — but will slowly, over years, be taken over by other plants.
Canadian thistle is considered a noxious weed across the United States, but it is classified that way mostly because of political pressure rather that for what it does (if nothing else it is a very visible, nasty looking plant). People may get scratched up, but you won’t hear about anyone dying from Canadian thistle poisoning. As an agricultural weed it can be significant, but usually pales in comparison to other weeds. Because it is listed as a noxious weed some states and local governments have tried to rein it in, at least over small areas, but this thistle is very resistant to herbicides, and tough to kill just by pulling, and so efforts are often fruitless.
Should we redouble our efforts and assail this thistle with more energy? I just can’t bring myself to say yes. This weed may be undesirable, but to put much money into a losing battle with a weed that has been here for about 400 years and that mostly affects disturbed sites seems like a silly strategy. In my mind we should be treating this weed as undesirable, but not nearly at the same level as other invasive or noxious plants.</d