Canada Thistle, Invasive Garden Weed

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Canada Thistle, I’ve come to learn, is an invasive garden weed. My first encounter with Canada Thistle occurred when it sprouted in the middle of a rose bush. Over the course of the growing season I noticed it, but couldn’t reach it, so I let it grow in the garden. Eventually, I figured I’d let it grow because a thistle would attract bugs that would be interesting to photograph. 
When it bloomed I was pleasantly surprised by the number of pollinators it attracted. Bees, moths and butterflies foraged in the blooms, and didn’t even seem to mind me invading their space with my camera. One hot summer day I got really close to the blooms and was captivated by their scent. A weed that bloomed, attracted pollinators to my garden and was scented? I had just hit the garden lottery. 

Unfortunately, it was nothing like what I imagine winning the lottery would be like. Canada thistle is a rhizomatous perennial that quickly spreads into the lawn, garden beds and thrives in places like empty lots. Besides spreading through an underground root system, it also spreads by seeds. Unlike other thistles, that are biennials and so easier to control, this one seems to require a lot of effort to keep under control and try to eradicate. Since I don’t use chemicals in my garden I try to be vigilant and cut off the above ground shoots I see in the garden with the edge of my shovel.

Illinois is one of 43 states that list Canada thistle as a noxious weed, this means that you are required to remove or control it if it is growing on property you own.  Check out that link to identify Canada thistle seedlings in your garden.  

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