Canada thistle (cirsium arvense, also known as Creeping thistle in Europe and in Australia as California thistle) is one of my favorite pasture plants for a number of reasons:
• It’s alfalfa-like in nutritional value.
• It is very resilient. It spreads via seeds and roots. It can grow in all kinds of climates, soils and precipitation levels, so it’s always there for us when we need some extra forage.
• It’s really easy to teach livestock to eat it. In fact, I think of Canada thistle as the “Gateway Weed.” Once cattle are eating it, they look at everything else in their pasture in a different way and begin to sample and graze a little of everything.
• Its flowers are pretty, they smell good, and they’re great for bees.
But not everyone appreciates Canada thistle they way I do. In fact, we’ve got a long history of hating it. Sir Anthony Fitzherbert, who published the very first farming manual in English in 1573, said that “thistyll was one of the weeds that greue mooste.” Carolus Linnaeus who developed the first weed classification system in 1753 considered it “the greatest pest of our fields.” In fact, people have disliked this plant for so long that before Canada existed, its name was “Cursed thistle.”
Cursed thistle immigrated to North America in the 1600s with the pilgrims. The list of laws requiring people to control it started with Vermont in 1795. By the 1800s it was so common in Canada that people assumed it was native, and that’s probably how it got the name we call it now. By 1865, the plant had become such a problem to farmers, that Canada enacted the first legislation for eradication of a weed: The Canada Thistle Eradication Act of 1865. By 1868 the state of Iowa wrote its own legislation declaring: “…that if any resident owner of any land in this state after having been notified in writing of the presence of Canada thistles on his or her premises, shall permit them or any part of the root to blossom or mature, he or she shall be liable to a fine of five dollars and cost of collection for each offense.” We’ve tried hard to comply with the laws we’ve made for ourselves, but our “enemy” has resisted mightily. It has even developed resistance to 2,4-D, the herbicide most commonly used to control it back in the 1960s.
Maybe it’s just because I’m from Colorado, (where as you all know, another kind of weed was recently legalized), but I’m wondering if it’s not time for us to take another look at Canada thistle. Is it time for us to legalize this weed? We made the laws, and we can remake them if we choose. So, just like my 1976 classmates and I did in high school debate class when assigned the topic of “Should we legalize weed?” let’s consider a few of the arguments about “legalizing Canada thistle.”
Canada Thistle is a Gateway Weed
I already admitted that yes, it is a gateway weed. I look at this as a good thing, because once livestock are eating this weed, they begin to eat everything else in their pastures. This means more forage for the livestock, and less time and money spent by producers trying to control something that we’ve not had success controlling since it arrived in North America.
On the other hand, there are times when this weed should be controlled. It IS a pest in crops and gardens. Perhaps we need different laws? Maybe like the medical marijuana laws some states have, we could have forage weed laws that provide for their use as forage, but govern how they are managed in and near crop settings.
Canada Thistle Would Increase
And you say this like it’s a bad thing. 😉 All I can say is “More Forage, More Forage!”
I’m not sure that it’s our laws, nearly as much as it is our culture that keeps us battling this plant. I guess we’d have to ask producers, “If we legalized this weed, or any other weed, would you gladly throw up your hands and let weeds have the run of your place?” I’m guessing the answer would be “No,” but it’s always a good idea to use a little bit of science to give us answers to questions before me make big changes.
There Are Health Impacts Associated with Livestock Grazing Canada Thistle
Canada thistle is a nitrate accumulator and if livestock have nothing else to eat, or if their rumens have not had the time to adjust to grazing them, the resulting nitrite poisoning can kill ruminants. This means that if we begin to look at these weeds as forage, we also need to understand how to work with our livestock to protect their health.
If Canada thistle were legalized, one of the impacts could be that folks selling herbicides might see a downturn in sales. These are people who have done us the service of providing us weapons in our War on Weeds, and their families and communities rely on their incomes as part of the economic fabric.
On the other hand, if producers have more forage and have to spend less on weed management, perhaps they’d make more money to add to their communities in other ways. Maybe the way they spend that extra money would even create new, different and even better jobs for the people who once sold them herbicides.
Maybe You Don’t Have to Legalize It – Just Eat It!
Even though we know that in the United States it’s the people who make the laws, the process we use takes us through all kinds of elected officials, and the process for creating a new law or remaking an old one can be labor intensive and time consuming. Perhaps we can avoid all that effort and just turn to grazing these weeds in pasture. There’s no law against that.
Here’s a reminder that I didn’t include when we first posted this article: I’m the person that came up with a simple method for teaching livestock to eat weeds. It takes as little as 8 hours spread over 7 days and once your livestock have been introduced to one weed, they’ll decide on there own to eat other weeds they find in pasture. They’ll teach their offspring and herd mates to do it too, so basically all you have to do is train one bunch of animals, just once, and you’ve created a weed eating herd that will work for you for the rest of your time on the farm.
Since it’s spring, and we’re getting ready for all those weeds to pop up, I’m going to do what weed dealers have done for decades: I’m going to make it easy and cheap to get you into the habit of your livestock eating weeds. You can choose your entry level: free, $35, or $50. (And some of the proceeds go to support On Pasture!)