SavATree - Tree Shrub and Lawn Care

Canada thistle is a noxious weed that’s hard to control in Colorado

Chances are you’ve probably seen this pesky weed around your property but just weren’t sure what it was called.

It’s called Canada thistle (Cirsium arvense) and it’s a noxious weed very common on properties in Colorado. Its leaves contain tiny little “thistles” meant to ward off animals who might be looking for something to munch on, as well as humans trying to pull the weed out with their bare hands.

Native to southeastern Eurasia, it was introduced to Canada as a contaminant of crop seed in the early 1600s and is known to be the most widespread of all thistle species.

Shoots are typically one to three feet tall, with tiny purple flowers about the size of a dime, producing seeds that often are not viable for reproduction.

You’re probably asking if the seeds rarely produce a healthy new thistle plant, why are they so prevalent on properties? The answer may surprise you.

A single Canada thistle plant can produce some 364 feet of roots and 26 additional stem shoots after only 18 weeks, making it very difficult to control.

Don’t be fooled into thinking that the roots you pulled out from the ground with the plant foliage means your troubles are over. Because of the extensive and often deep root system, even the smallest remaining roots can grow into a new noxious weed plant.

So, how can you combat Canada thistle on your property? The answer is it takes patience and perseverance.

The best defense is to make your yard and garden less accommodating to Canada thistle. While they typically will grow anywhere, they prefer soils that are low in fertility with wide open spaces.

Proper lawn and soil fertilization will certainly make your property less desirable. Additionally, overseeding your lawn to prevent any bare spots and adding layers of mulch to cover the soil in flower beds will create less than ideal conditions for Canada thistle to thrive.

Chemical applications have also proven to be successful, but remember they take time and consistent application in order to fully eradiate the problem.

While hand picking is encouraged when a Canada thistle pops up here and there, larger infestations may require a visit from the professionals in order to develop a plan to rid your property of this common Colorado noxious weed once and for all.

Contact SavATree today for help with your Canada thistle problem.