When my parents moved to Idaho a few years ago, they received quite a welcome. Before they finished unpacking their boxes, a blast of cool wind blew through the night. When they awoke the next morning, the yard was covered in tumbleweeds, stacked neck-high. My parents spent the next day bagging the brittle plants up.
A similar scene was caught on video last week and has gone viral online. In the short clip above, a slew of tumbleweeds can be seen blowing across a field in Bozeman, Montana, according to the uploader. (See more photos of tumbleweeds.)
Although tumbleweeds have been nearly ubiquitous in much of the American West for more than a century, they’re not native. The plant, Salsola tragus, is more properly called Russian thistle, and it is an invasive import from the Russian steppes (east of the Ural Mountains).
Tumbleweeds grow in the ground through much of the year, but in winter, they die. The stems become brittle. When a strong wind whips up, they break off and roll across the landscape, in order to scatter their seeds far and wide. The plants can grow nearly as large as a small car and each can spread as many as 250,000 seeds, George Johnson writes in National Geographic magazine.
With the spring snowmelt and the first summer rains on the ranch, thousands of Russian thistle seeds began to erupt into the sunlight, appearing against the brown earth like tiny blue-green stars. They looked so pretty and innocent, the young ones, basking in the sun. Then they began to transmogrify. In a few days they were the size of my hand, their rubbery, purple-veined fingers pulling back troll-like as I tried to yank them from the ground. They weren’t yet ready to go.
Tumbleweeds were first identified in the American West in 1880. At the time, some people thought the pesky plants were intentionally introduced by subversive elements. But government scientists think Russian thistle was introduced accidentally with flax seeds for planting.
The weeds can pose obstruction problems and increase fire risk along roadways and in yards, as my parents discovered. They can also suck up large amounts of water, competing with native plants or crops. They can lead to increased soil dryness, which can promote erosion.
Russian thistle has spread across much of the western U.S. and Canada. It’s also now found in Argentina, Australia, and Eurasia. For years, scientists have been working on ways to control the obnoxious weed through biological controls, such as weevils, mites, or fungi. So far herbicides remain the most effective treatment.