by Rob Sproule
I love spy movies, ones like James Bond where the cars are fast, the suits expensive and you never know which beautiful woman you can trust. When I see Himalayan Impatiens, the noxious weed that’s usually planted deliberately in Alberta yards, I think of those double agents and how alluring they can be.
Also called Himalayan Balsam, Kiss-Me-On-The-Mountain, and Ornamental Jewelweed, this beautiful weed can escaped the backyards they’ve been planted in and are clogging Edmonton’s ravines and river valley. Fast growing, they monopolize scant water and pollinators and form dense, 2′ thickets that native plants can’t penetrate.
What is it?
Hailing from the rugged Western Himalaya where they’ve had to develop potent survival and reproduction habits to survive, they were introduced as an ornamental plant. It’s been reported across Canada and is most alarmingly prolific around ponds, riverbanks, and other wetlands.
Himalayan Impatiens are running rampant in Alberta because people don’t know who they really are. Masquerading as sultry double agents, they’re available at plant swaps and even the odd greenhouse, billed as a showstopper that can’t be killed.
As an annual, it dies back completely in the winter and grows quickly from seed the following spring. The die back creates an erosion problem along river and creek banks. The aggressive Balsam chokes out native perennials in the summer and, during early spring rains, there’s no significant root system to hold soil from leeching into the waterway.
Chances are you’ve seen them while you were walking. They look like pretty, albeit exotic wildflowers with tall, narrow, reddish stems often crossing 6 metres high. Like a young Bond drawn to the mysterious brunette with the Beretta in her purse, you’ll remark to yourself how beautiful they are and wonder where you can get one for your own garden. Don’t be tempted!
The pink flowers, appearing between June and September, are shaped like an old-school British “Bobby” helmet. They fade to 3cm long seed pods that explode like grenades when touched, scattered seeds as far as 7 metres.
Getting Rid of it
Himalayan Impatiens should be easy to stop. Most weeds, from Quackgrass to Bellflower, deploy insidious subterranean rhizomes, which creep like submarines until they find an opportunity to surface and grow. Jewel weed only reproduces by seed, and is rendered useless with a simple pinch of the blossom.
The problem arises with its attractive flowers. Sold as a “Poor-Man’s Orchid” from the mid 19th century in England, it’s long been popular for it’s showy pink blooms. If you didn’t know what the plant was, you’d be reluctant to pinch them.
If allowed to seed, Jewel weed produces 600-800 of them that it disperses violently, in true Impatiens fashion, over a wide radius. The resultant weed clumps become so dense that other plants can’t penetrate.
To get rid of it, simply expose the double-agent. Remind yourself that looks aren’t everything as you pull it, garbage it, and watch for other seedlings to pop up. As long as you nip it before it blooms, your problem will resolves itself quickly (unless your neighbour has one, in which case the seeds will launch themselves into your yard).