Invasive arundo takes hold in Virgin River system, control efforts underway

WASHINGTON COUNTY – What was once a plant sold locally for landscape use has escaped into the wild and become the latest invasive species of concern in the Virgin River Basin.

Healthy arundo growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate
Healthy arundo growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate

The giant reed, arundo donax, was first introduced to the western United States by Spanish settlers but is now destroying riparian ecosystems and clogging waterways.

Arundo, also known as wild cane, grows rapidly and can reach more than 20-30 feet. It grows in large stands along rivers and streams, taking over natural habitat, pushing out native plants, animals and insects and using a lot of water.

The reed is a flood and fire hazard. Arundo stalks break off during floods and get caught on bridges and other river structures, adding to the flood debris and causing damage. Arundo is also highly flammable and poses a fire hazard, especially in urban areas.

“The challenge is this is a very resilient plant,” Jake Powell, Utah director of the American Conservation Experience, said.  “Scarily resilient, terrifyingly resilient.”

In California, dead stalks of arundo have been observed sitting in salt water for months, then floating up on an island and taking root, Powell said.

This arundo has been treated with an herbicide. It is growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate
This arundo has been treated with an herbicide. It is growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate

“A live one breaks off, floats downstream and lodges, and then a foot of sand goes across it,” Powell said. “We might have surveyed it last year and it was just a sandy beach. Well, then, this year, there’s four or five stalks coming out of this plant.”

Arundo was first found along the Virgin River in Confluence Park, which lies within the City of Hurricane and LaVerkin City; and in LaVerkin Creek, Steve Meismer, local coordinator for the Virgin River Program, said.

“It wasn’t until after the 2005 flood event that we really started seeing it show up more and more down the river,” Meismer said.  Downstream from Confluence Park, 200-300 large clumps of arundo were found within eight miles.

For the past three years, volunteers from the American Conservation Experience have been working hard, cutting and removing the plants by hand and treating the remaining stumps.

A dead clump of arundo which has been treated and removed by American Conservation Experience crews, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate
A dead clump of arundo which has been treated and removed by American Conservation Experience crews, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate

So far, nearly 80 miles of riverbed have been treated: Sixty miles of the Virgin River, 15 miles of the Santa Clara River and shorter stretches of LaVerkin Creek and Fort Pearce Wash, according to the Washington County Water Conservancy District.

“From the border of Zion National Park all the way down to the Arizona border was all surveyed,” Powell said, “and the tributaries of the Santa Clara, LaVerkin Creek, Ash Creek … Fort Pearce Wash,” Powell said.

“A lot of it was done on foot, in the river, walking the floodplain, very arduous, tedious labor.”

After the arundo is cut, herbicide is applied to the plants by hand, Powell said. American Conservation crews have spent 3,444 hours removing 1,619 clumps of arundo; volunteers along with several local, state and federal agencies have helped the effort.

A healthy cluster of arundo plants grows on a hillside on the northwest corner of Industrial Road and Red Hills Parkway in St. George, Utah, Aug. 31, 2016 | Photo by Julie Applegate, St. George News
A healthy cluster of arundo plants grows on a hillside on the northwest corner of Industrial Road and Red Hills Parkway in St. George, Utah, Aug. 31, 2016 | Photo by Julie Applegate, St. George News

“This was a first giant leap, and then we’ll be taking steps further,” Powell said. All the partners are committed to staying on top of the problem, he said.

“It’s like any weed, any invasive species, it’s not a once-and-done thing, it takes constant attention,” Powell said.

Noxious weed

Arundo was declared a Class 1B noxious weed by the Utah Department of Agriculture and Food in 2014. Plants in this category pose a serious threat to the state and are considered a very high priority.

An invasive species mitigation grant from the Department of Agriculture is funding the removal efforts.

“It was basically a grant that was intended to get ahold of some of these problem species as early as possible so that they didn’t become bigger problems down the road,” Meismer said.

The project is helped by the fact that arundo doesn’t seed in Southern Utah, so removal efforts can focus on the plants and its roots, or rhizomes.

This arundo has been treated with an herbicide. It is growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate
This arundo is stunted and deformed after being treated with an herbicide. It is growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate

Stands of arundo are cut, the canes are removed and hauled to the landfill. If washed downstream the fragments can reroot and start the cycle over again.

“So it becomes a species that you have a chance of keeping it in spots (controlling),” Powell said. “This plant was identified as a plant that if we jumped on it quickly we could address it before it became an issue.”

In California, arundo is choking waterways and destroying entire riparian ecosystems, Powell said.

American Conservation Experience has been working on the arundo project for three years. The organization is a conservation corps, Powell said,  a modern, nonprofit version of the Civilian Conservation Corp that operated in the 1930s during the Great Depression.

“We take young people, they volunteer with us through the AmeriCorps program and they come to us and work for three to six months doing conservation-type projects,” Powell said.

Typical projects AmeriCorps works on include building hiking and mountain biking trails, clearing irrigation ditches and other labor-intensive projects for Dixie National Forest and Zion National Park.

“There’s no easy, pretty way to get rid of this (arundo),” Powell said.

This arundo is stunged and deformed after treatment with an herbicide. It is growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate
This arundo is stunted and deformed after treatment with an herbicide. It is growing near the Virgin River in Confluence Park, LaVerkin, Utah, Aug. 31, 2016 | Photo by Julie Applegate

“It takes hundreds of hours on hot miserable days to get it done,” Powell said, “and so that’s why we got involved.”

Arundo was sold commercially in nurseries for use in residential landscapes until just a few years ago, Meismer said, but by the time arundo was banned, it had escaped into the Virgin River ecosystem.

Escape into the wild is as simple as a child picking up a stalk and then discarding it in the river.

“It’s just that easy, that something like this can go from ‘hey, we’ve knocked it all out of here,’ to, one piece and you’re back to the same problem again,” Meismer said.

Any local resident that wants to report the location of arundo in the wild or have it removed from their property can call Meismer at the Water Conservancy District office, telephone 435-673-3617.

“Give me a call, we’re willing to come in, get rid of it for you. We’ll come in, cut it down, treat it,  herbicide it,” Meismer said.

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Email: japplegate@stgnews.com

Twitter: @STGnews

Copyright St. George News, SaintGeorgeUtah.com LLC, 2016, all rights reserved.

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2 Comments

  • .... September 7, 2016 at 9:47 am

    Bob has a lot in common with the arundo plant. lmao. now that’s funny right there. !

  • Common Sense September 7, 2016 at 1:47 pm

    makes me think of bamboo

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