Tuesday, February 6, 2018

Street Plants: Tumbleweeds Come to Town

Plant on a mission.

Tumbleweeds are iconic of the American West, where they tumble and roll for miles across open country, get trapped for awhile in a draw or fence, and then travel again when a strong blast of wind sets them free. The archetypal cowboy finds comfort in tumbleweeds, seeing in them kindred spirits, and companions for his own restless wandering.

But not me. I see them as plants on a mission. I live on the west edge of town, so whenever the wind blows hard, tumbleweeds come flying in from places where last year they managed to get established and grow—like railroad beds, ditches along the highway, and especially the disturbed fields of the Wyoming Territorial Prison (tourist attraction). Being annals, they died last fall. But it's in death that tumbleweeds become “active.”

Breaking from their roots, they race along, driven by the wind, each one dropping thousands of seeds as it rolls. They pile up along my fences, behind the trash and recycle containers, under the car, in tree canopies, and especially at the end of the hedge which must be directly in their path. But I don't mind. They're fascinating—impressively well adapted.
Tumbleweeds coat the west side of a six-foot-tall hedge.
“Tumbleweed” is a strategy, not a specific plant. We have three common ones: Russian thistle, tumble mustard, and kochia (Salsola kaliSisymbrium altissimumKochia scoparia). Thousands of tumbleweeds fly into town every season; multiply this by thousands of seeds each and it’s guaranteed that even in urban environments a good number of seeds will land on patches of bare dirt, from tiny to large. Some will germinate, and a few will grow into plants with seeds to drop as they themselves roll on. So tumbleweeds are street plants too, not just icons of the West. They’re tough opportunists able to thrive where little else grows … scrappy waifs generally overlooked (just as well; most people have little use for them) and hardly ever appreciated.
Kochia during the growing season, in a crack between street and curb.
Russian thistle thrives on its own dirt pile.
Many tumbleweeds are still rooted, so there will continue be a steady supply.

Russian thistle and tumble mustard.

Lucy of Loose and Leafy in Halifax has kindly taken up the street plant cause again, encouraging plant lovers to look closely in places we usually ignore. For this month’s virtual gathering, I’ve been looking for green street plants. But no luck, even with our weird warm winter. However I did find lots of tumbleweeds. No surprise—we’ve had such strong winds lately, with average speeds in the 30s (mph) and gusts in the 40s and 50s.
One even reached the protected yard off the sunroom.

About once a month (this time of year) I put on heavy gloves, gather up the tumbleweeds in my yard, take them across the street to the abandoned railroad right-of-way, and set them free so that they can continue on their merry way.
Cleaned out from hedge.
Off to Nebraska!