Trouble with Tumbleweeds

Tumbleweed in Marsh, Courtesy and Copyright Anna Bengston
Tumbleweed in Marsh
Courtesy & Copyright Anna Bengston

Immortalized on the sets of old western movies, the tumbleweed has long been a classic symbol of the rugged, wide-open landscapes of the American West.  As a result, we can all easily recognize the spherical skeletons when we come across them caught on underbrush or piled up on fence lines here in Utah.  But this archetype is not an accurate representation of typical western United States or Utah flora, because tumbleweed– or Russian thistle –is an invasive weed.

The story begins in the late 19th century, when South Dakotan farmers reported seeing an unknown plant growing in their croplands.  Years later, it was identified as Russian thistle, scientific name Salsola tragus, a native plant of Russia and the Eurasian steppes east of the Ural Mountains.  It had been accidentally brought to the United States in a shipment of flaxseed.  By the time the U.S. Department of Agriculture published its inquiry into the plant in 1894, about 20 years after the plant’s introduction, 35,000 square miles of land had become “more or less covered” in Russian thistle.  Since that time the plant has spread into every state except Florida and Alaska.

So what is the problem?  Russian thistle, despite the nostalgic connotations of the old west it inspires, is a pest.  It easily takes root in disturbed or bare ground, moving in before native species are able to establish.  Drought conditions like those we have had in recent years only promote the plant’s proliferation.  The dryness hinders the growth of crops and native species, while the Salsola seed requires very little moisture in order to germinate and grows in where the crops and native species otherwise would have.  This can have deleterious effects on cropland and natural ecological functioning. Not to mention the wildfire risk the dry plant debris poses.

Salsola’s sheer numbers have also turned into more than just a nuisance.  Each plant may bear some 250,000 seeds that can be spread across miles as they drop off the rolling tumbleweed.  Consequently, we see images like those from Colorado earlier this year depicting piles of tumbleweeds filling streets, covering cars, and climbing the walls of houses.  In one instance, a windstorm clogged a town in New Mexico with 435 tons of the weed.

Utahns have yet to experience the full effects of this plant’s troublesome nature, but this does not mean we are immune; Russian thistle has been reported in every county of the state.  Luckily, for those fighting this plant’s advance, technology and research are on our side.  Several biological control options– from insects to fungal pathogens –are being tested as methods of natural Salsola population suppression with encouraging results.  But, all in all the management principles have not changed much since 1894: prevent the production and dispersal of seed across all infested areas.

For Wild About Utah, I’m Anna Bengtson.

Credits:
Image: Courtesy and Copyright Anna Bengston
Text: Anna Bengston

Sources & Additional Reading:

Banda, S. (2014, April 9). Tumbleweed troubles: Colorado drought creates perfect storm for road-clogging weeds. . US News. Retrieved May 2, 2014, from http://www.usnews.com/news/us/articles/2014/04/09/colorado-tumbleweeds-overrun-drought-areas

Coffman, K. (2014, March 27). Tumbleweeds plague drought-stricken American West.Reuters. Retrieved May 2, 2014, from http://www.reuters.com/article/2014/03/27/us-usa-tumbleweeds-idUSBREA2Q14E20140327

Dewey, L. (1894). The Russian thistle : its history as a weed in the United States, with an account of the means available for its eradication. U.S. Department of Agriculture, Division of Botany, Washington: Government Printing Office. Retrieved May 2, 2014, from https://archive.org/stream/russianthistleit15dewe#page/n5/mode/2up

EDDMapS. 2014. Early Detection & Distribution Mapping System. The University of Georgia – Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed May 1, 2014.

Gilman, S. (2014, February 11). Troubleweeds: Russian thistle buries roads and homes in southeastern Colorado. . — High Country News. Retrieved May 2, 2014, from http://www.hcn.org/blogs/goat/troubleweeds-russian-thistle-buries-roads-and-homes-in-southeastern-colorado

Gilman, S. (2014, March 17). A plague of tumbleweeds: A handy pamphlet on how to dig out from a tumbleweed takeover of sci-fi proportions. . — High Country News. Retrieved May 2, 2014, from http://www.hcn.org/issues/46.5/a-plague-of-tumbleweeds

Main, D. (2011, March 2). Consider the tumbleweed. » Scienceline. Retrieved May 2, 2014, from http://scienceline.org/2011/03/virtues-of-a-weed/

Mazza, E. (2014, April 9). Tumbleweeds Reclaim West Amid Drought, Blocking Roads And Canals. The Huffington Post. Retrieved May 2, 2014, from http://www.huffingtonpost.com/2014/04/09/tumbleweeds_n_5115734.html

Ostlind, E. (2011, March 9). Tumbling along. — High Country News. Retrieved May 2, 2014, from http://www.hcn.org/blogs/goat/tumbling-along

Ostlind, E. (2001, May 20). It may be High Noon for tumbleweed. — High Country News. Retrieved May 2, 2014, from http://www.hcn.org/wotr/it-may-be-high-noon-for-tumbleweed

Russian Thistle (Salsola tragus). (n.d.). Russian Thistle (Salsola tragus). Retrieved May 2, 2014, from http://www.blm.gov/ca/st/en/fo/hollister/noxious_weeds/nox_weeds_list/russianthistle.html

USDA, NRCS. 2014. The PLANTS Database (http://plants.usda.gov, 8 May 2014). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Dyer’s Woad

Click to view a larger picture; Dyer's Woad in blossom courtesy and copyright 2009 Brad Kropp - as found on bugwood.org
Dyer’s Woad in blossom
Courtesy of and
Copyright © 2009 Brad Kropp
As found on bugwood.org

In early May, pale yellow carpets some hillsides of Northern Utah. The plants are a non-native known as Dyer’s Woad. This Asian member of the cabbage family has been cultivated as a dye and medicinal plant in Europe and Asia for 2000 years. Dyer’s Woad produces a glorious blue dye, but the process is tricky. No synthetic dye equals the color and characteristics of woad dyes.

Woad had arrived in Utah by 1932 as a seed contaminant. Now it is a noxious weed. Woad has a number of unique abilities that contribute to its vigor. Being a biennial plant, it spends the first year of life as a rosette of leaves, building reserves. In its second year, those reserves allow a woad plant to send forth a tall, lanky stem covered with pale yellow flowers that ultimately yield up to 10,000 seeds per plant.

Although Dyer’s Woad is not toxic, few animals relish it either. The seeds have chemicals that inhibit germination and root elongation in other plants, giving woad a competitive edge. Woad causes millions of dollars in losses each year, so control is a major issue. Herbicides and mechanical removal are best used against the rosettes, but nature has provided a native fungus that views woad as dinner. This rust fungus is very effective at eliminating or severely reducing seed production. Plants infected with the rust fungus are misshapen, wrinkly, and covered in dark spots. Those spots brim with rust spores. Therefore, when removing woad, leave the sickly plants to infect yet more woads.

Click to view a larger picture; Dyer's Woad with rust courtesy and copyright 2009 Brad Kropp - as found on bugwood.org
Dyer’s Woad with rust
Courtesy of and
Copyright © 2009 Brad Kropp
As found on bugwood.org

This is Linda Kervin for Bridgerland Audubon Society.
Credits:
Photos: Brad Krupp, Utah State University, Bugwood.org
Text: Michael Piep, Utah Native Plant Society

Additional Reading:

Resources:
Intermountain Herbarium: http://herbarium.usu.edu/

Washington Weed Board: http://www.nwcb.wa.gov/weed_info/Written_findings

/Isatis_tinctoria.html

References:
Edmonds, J. 2006. The History of Woad and the Medieval Woad Vat. http://www.lulu.com/product/paperback/the-history-of-woad-and-the-medieval-woad-vat/4928037

Shaw, R.J. 1989. Vascular Plants of Northern Utah. Utah State University Press, Logan, Utah. http://www.usu.edu/usupress/books/index.cfm?isbn=1417

Welsh, S.L., N D. Atwood, S Goodrich & L.C. Higgins. 2008. A Utah Flora, 4th Ed. Brigham Young University, Provo, Utah. http://www.amazon.com/Utah-Flora-Stanley-L-Welsh/dp/0842525564

Dyer’s Woad

Dyer’s Woad in blossom
Courtesy of and
Copyright © 2009 Brad Kropp
As found on bugwood.org

In early May, pale yellow carpets some hillsides of Northern Utah. The plants are a non-native known as Dyer’s Woad. This Asian member of the cabbage family has been cultivated as a dye and medicinal plant in Europe and Asia for 2000 years. Dyer’s Woad produces a glorious blue dye, but the process is tricky. No synthetic dye equals the color and characteristics of woad dyes.

Woad had arrived in Utah by 1932 as a seed contaminant. Now it is a noxious weed. Woad has a number of unique abilities that contribute to its vigor. Being a biennial plant, it spends the first year of life as a rosette of leaves, building reserves. In its second year, those reserves allow a woad plant to send forth a tall, lanky stem covered with pale yellow flowers that ultimately yield up to 10,000 seeds per plant.

Although Dyer’s Woad is not toxic, few animals relish it either. The seeds have chemicals that inhibit germination and root elongation in other plants, giving woad a competitive edge. Woad causes millions of dollars in losses each year, so control is a major issue. Herbicides and mechanical removal are best used against the rosettes, but nature has provided a native fungus that views woad as dinner. This rust fungus is very effective at eliminating or severely reducing seed production. Plants infected with the rust fungus are misshapen, wrinkly, and covered in dark spots. Those spots brim with rust spores. Therefore, when removing woad, leave the sickly plants to infect yet more woads.

Dyer’s Woad with rust
Courtesy of and
Copyright © 2009 Brad Kropp
As found on bugwood.org

This is Linda Kervin for Bridgerland Audubon Society.
Credits:
Photos: Brad Krupp, Utah State University, Bugwood.org
Text: Michael Piep, Utah Native Plant Society

Additional Reading:

Resources:
Intermountain Herbarium: http://herbarium.usu.edu/

Washington Weed Board: http://www.nwcb.wa.gov/weed_info/Written_findings

/Isatis_tinctoria.html

References:
Edmonds, J. 2006. The History of Woad and the Medieval Woad Vat. http://www.lulu.com/product/paperback/the-history-of-woad-and-the-medieval-woad-vat/4928037

Shaw, R.J. 1989. Vascular Plants of Northern Utah. Utah State University Press, Logan, Utah. http://www.usu.edu/usupress/books/index.cfm?isbn=1417

Welsh, S.L., N D. Atwood, S Goodrich & L.C. Higgins. 2008. A Utah Flora, 4th Ed. Brigham Young University, Provo, Utah. http://www.amazon.com/Utah-Flora-Stanley-L-Welsh/dp/0842525564