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The usual definition of a weed is a plant growing where you don’t want it.   Identifying what's a weed, however, takes a bit more effort. Photo courtesy Donna Balzer/For CREB®Now
The usual definition of a weed is a plant growing where you don’t want it. Identifying what's a weed, however, takes a bit more effort. Photo courtesy Donna Balzer/For CREB®Now

Aug. 08, 2016 | Donna Balzer

Crazy weeds

When you know it's too good to be true

newDonnaweb"Help! This plant is growing behind my office in Calgary and I can't identify it" tweeted Christene.

Gloria had some "wonderful old flowers" suddenly appear in her Canmore yard, so she sent photos by email. Mehran fell in love with a beautiful plant he saw in a Springbank ditch. He texted me a photo. Pretty and mysterious plants were suddenly on all my media.

"Our office building is about two blocks west of the Bow River. There's always a bunch of interesting plants growing out back behind the warehouse loading dock so I'm always trying to identify them, see if there are any plants I can steal to put in my garden. I had never seen anything like this one before and probably spent a good hour trying to figure out what it was," said Christene by follow-up email. But of course anything this exotic and pretty and springing out of nowhere could only be one thing. Christene and Gloria and Mehran all had or wanted to know more about weeds. Pretty, vigorous weeds.

The usual definition of a weed is a plant growing where you don't want it. That's why the edible and nutritious dandelion, while endangered and rare in its native Switzerland, is a weed in Calgary lawns and boulevards. We don't want it so that makes it bad even though it is also a great wildlife plant, providing nectar for bees early in the spring.

But dandelions are easily recognized and the photos arriving in my inbox were something completely different and potentially dangerous.

Black Henbane (Hyoscyamus niger) is armed and dangerous. It's smell is so powerful it makes you giddy. If you decide to pull it out wear gloves. Henbane is an introduced noxious weed by definition of the provincial government ( "Symptoms of poisoning include impaired vision, convulsions, coma, and death from heart or respiratory failure" according to the Alberta Invasive Plants website. In other words close contact with Henbane could drive you crazy.

This relative of the potato and tomato has been showing up in Calgary's paths and natural areas this month. If you see an unknown showy plant with yellow flowers it might be henbane. Don't go near it.

The second noxious weed, observed by both Gloria and Mehran is Hesperpis matronalis, also known as Dame's Rocket. It is found commonly in Calgary's older parks and gardens and often included in wildflower mixes.

Both plants are biennials - they sprout in one year but they don't bloom and spread seeds until the next year. Dame's Rocket's lovely purple blooms wave at you in the breeze like a buddy as you drive along country roads. But it is classed as a noxious weed because it escapes cultivation so easily and has become a nuisance. So, by law, if you have either weed pull it out.

"You were so very helpful to me in identifying these weeds that I had thought were wonderful old flowers. Thanks again Donna. My weeds have now been destroyed properly," said Gloria by email.

These weeds are pests, not just pretty plants. And that means they need to be removed or reported if spotted. Right away. Before you fall in love or go crazy.

Donna Balzer is an enthusiastic gardener and entertaining speaker. Sign up for her e-newsletter at or follow her on Twitter @NoGuffGardener.

Tagged: advice | backyard | Calgary Real Estate | Calgary Real Estate News | Donna Balzer | flowers | front yard | Gardening | gardens | growing | Guest Column | No Guff Gardener | plants | YYCRE

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