Arundo donax is to the plant world what “Species” star Natasha Henstridge was to her fictional prey: attractive, but destructive.
The ornamental Mediterranean plant, which is more commonly known as giant reed, can increase fire hazards, siphon groundwater out of aquifers and displace native plants and animals.
Thanks to some unwitting gardeners, the fast-growing perennial grass that grows up to 30 feet tall has found a home in Grand County. But with the help of a $3,000 grant from the Utah Weed Supervisor Association, county officials hope to eradicate it before it spreads to local waterways and beyond.
The county’s giant reed-control project targets the early removal of the species by helping local property owners pay for other plants that could take its place in their yards.
“We’d like to have them do more of the removal, and we’d get funding for them to get more replacement plants, so they can actually go and put something in its place,” Grand County Weed Supervisor Tim Higgs told the Grand County Council during its regular meeting on Tuesday, June 21.
Giant reed could be relatively easy to eradicate locally compared to other noxious or invasive species, since there aren’t many known infestations on public lands in Grand County – at least, not yet.
“This particular plant happens to be almost exclusively on private property – people’s yards,” Higgs said. “A lot of people mistake it for bamboo, but it’s not.”
It’s a different story along parts of the West Coast, where people in what is now Los Angeles used the reed as a roofing material and animal fodder as far back as the early 1800s, according to the California Invasive Plant Council. In the decades that followed, giant reed spread across California’s lower elevations and has since naturalized in many places between sea level and 1,000 feet, the plant council reported.
Grand County Council chair Elizabeth Tubbs said the name of the plant itself has an alarming ring to it.
“That sounds ominous: the giant reed,” Tubbs said.
While some proud gardeners might dispute that characterization, weed control specialists certainly think about it that way: Once it becomes established along creeks and other riparian areas, it takes over as a dominant species, eroding streambanks and degrading wildlife habitat in the process.
Higgs first received word last February that Utah now lists giant reed as a Class 1B weed in the state, joining the likes of Japanese knotweed, St. John’s wort and other non-native plants that currently have a limited foothold here.
Colorado also classifies giant reed as a noxious weed, and Utah Weed Supervisor Association President Aaron Eager said the Beehive State only joined its neighbor after an extensive public review period and careful scientific studies.
“It’s a difficult process when a plant actually gets put on the state’s noxious weeds list,” Eager told the Moab Sun News. “It’s not something that’s taken lightly or done very quickly.”
Now that the state has made its “noxious” status official, both Eager and Higgs hope to put a dent in the local giant reed population.
“We have a little bit that is down in the St. George area, but probably the largest infestation is in the Moab area,” Eager said.
Indeed, by Higgs’ count, there at least 100 documented infestations in Moab and Spanish Valley, as well as more than a dozen in Castle Valley and two in Thompson Springs.
“We have probably 10 times as much as the entire rest of Utah has, just in this valley,” Higgs said. “I think there are right around 10 or 11 in the (rest of) the state, and … I’ve seen two areas (near Moab) where people have recently planted it.”
Nurseries and greenhouses in Utah and Colorado aren’t supposed to sell giant reed, but some people continue to see its value as a decorative plant.
“People have used it as an ornamental,” Eager said. “It has a giant seed head that is pretty.”
In the past, researchers suggested that the plant’s seeds don’t germinate easily in North America, although Eager said that seed germination is one of two ways that the plant can spread. However, it’s more likely to gain a foothold by way of its extensive root system, or rhizomes, which can extend as far as 10 feet below the surface.
“Once it gets established, it will propagate faster through the root system,” Eager said.
Gardeners can control the plant with herbicides, or by manual and mechanical weeding, although Eager said they must be persistent and remove every single root segment, lest the reed continue to spread.
“The rhizomes are pretty extensive, but you can do it and try to dig it out,” Eager said. “But if you don’t get it all, they will grow out.”
With the grant funding now in place, Higgs and his department will launch an educational outreach campaign to let property owners and residents know what they can do to eradicate the weed.
“It’s actually going to probably be a multiple-year fund, depending on how the citizens in the community here react with it,” Higgs said.
If anyone balks at a request to remove giant reed from their yards, Eager suggested that county officials could launch into a discussion about native grasses and other plants that would look nice in their yards.
“I would say, ‘Is there something else that we can replace it with that is similar?’” he said. “I’m sure that there’s multiple options that they could do.”
But if the effort is going to succeed, he said, it’s important to engage the community in the dialogue.
“It’s got to be a two-way conversation,” he said. “I think that’s what Tim’s trying to do: not take the heavy-handed route.”
Grant funding will help homeowners replace giant reed with other plants
We have probably 10 times as much as the entire rest of Utah has, just in this valley … I think there are right around 10 or 11 in the (rest of) the state, and … I’ve seen two areas (near Moab) where people have recently planted it.