Home Notes From Kathy Canada thistle is my favorite forage. You can learn to love it...

Canada thistle is my favorite forage. You can learn to love it too!

Bees on Canada/Creeping thistle by Richard Bartz courtesy of Wikipedia
Bees on Canada/Creeping thistle by Richard Bartz courtesy of Wikipedia

Since developing a simple method for teaching cows and other livestock to eat weeds, I’ve trained lots of cows, goats, sheep and bison to eat most of our most problematic invasives. With all I’ve learned about weeds in that time, I’ve grown to love one more than all the rest: Canada thistle (cirsium arvense, also known as Creeping thistle in Europe and in Australia as California thistle).

It really is a GREAT Forage!

• It’s the nutritional equivalent of alfalfa without the bloat issues.
• It is very resilient. It spreads via seeds and roots, and 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.
• Its flowers are pretty, smell good, and are great for bees.
• 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. That means Canada thistle is a great tool for improving the quantity of forage you have – whether it’s the thistle or other pasture weeds. I talk more about the economics of all that in this week’s Money Matters article.

Lewistown, MT heifer eats Canada thistle in pasture.
Lewistown, MT heifer eats Canada thistle in pasture.

Great nutrition means great gains

Canada thistle is like candy to a ruminant. That’s what makes it so easy to teach. But the importance of this hit home at a conference I attended where a salesman was encouraging graziers to use his supplement tub.

“It’s 16% protein and will help your cattle gain 2.5 pounds a day!” he said.

“Wow!” I thought. “Canada thistle is that or better! Who knew that it could help stock put on so much weight?!”

As always, there’s a caution

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, there’s the potential for nitrate poisoning. This means 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.

To ensure your animals stay safe:

• Never put animals on a solid stand of this plant. They must have other forage to mix with it to prevent poisoning.
• Give rumen microbes time to adjust to this plant. Introduce the food in small amounts over a period of 5 to 7 days.
• Don’t put hungry animals into a field that is largely made up of this weed. Make sure they have a full stomach when moving to a new pasture with large stands of Canada thistle. This will ensure they have the necessary carbohydrates in their rumen to aid the rumen microbes in breaking down nitrate.

Here’s How to Get Started Benefiting From Canada Thistle

All it takes is a few hours of your time and it’s actually a lot of fun. I break down all the steps here:

How to Teach Cows to Eat Weeds in Just 8 Hours Over 7 Days

Thanks for reading about my favorite forage!



  1. I love it, too, at least as a feed. I’ve sent your articles to family east of Arizona. A few, in Alabama, are looking into things. When it’s cotton harvest, they have to hire people to cut out amaranth that grows like trees in the fields. A year or two in pasture with cattle and poultry would knock most of it out. Good article and again, it love thistle.

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