‘Pretty’ wildflower actually a weed
It’s pretty. It’s purple. It’s pleasant to look at. But it’s also a problem.
The purple loosestrife appears to be an attractive wildflower, but it is actually a noxious weed that Mesa County officials are trying to eliminate — and they are asking residents for help.
“It’s really a pretty plant, but they displace native plants and wildlife,” said Melissa Werkmeister, Mesa County weed and pest coordinator.
Native to Europe, the purple loosestrife was introduced to North America as an ornamental garden plant but has escaped to natural areas and is now threatening native species. It competes with the native loosestrife plant, and it grows well in areas with slow-moving or shallow standing water, often growing near cattails. It has popped up in numerous places around the valley, especially along the river and near irrigation ditches.
“We are looking for it, and have money and manpower to kill it. We also go out on the river to search for and destroy it,” Werkmeister said.
Mesa County also works cooperatively with Grand County, Utah, to go out on the river and eliminate the plant. Workers try to cut the flowers off before they go to seed and use an aquatic-safe herbicide to get rid of the rest of the plant.
Purple loosestrife is a perennial and begins flowering and setting seed between June and August.
The plant can grow up to nearly 10 feet and can produce millions of seeds, which can remain viable for 20 years. The species rapidly replaces native vegetation and has little wildlife value, officials say. It can also grow across irrigation drainage ditches and disrupt water flow.
“It’s one of the top species we go after,” Werkmeister said.
All together in the state, there are roughly 60 noxious weed species the Colorado Department of Agriculture manages.
In Mesa County, 19 different weeds pose a threat to native species, and the local noxious weed task force focuses on eliminating six of them. The purple loosestrife and yellow starthistle remain at the top of that list, Werkmeister said.
The elimination of these invasive species is part of the Colorado Weed Management Act. Mesa County’s efforts to eliminate noxious weeds are funded by the Colorado Department of Agriculture.
The goals of the noxious weed program are to prevent the introduction of new invasive plant species, eradicate species with isolated or limited populations and contain those invasive species that are well-established and widespread.
“We just have the approach where it’s educational and let people know what they have, ‘cause they may not realize what they have,” Werkmeister said.
If residents suspect they have purple loosestrife growing nearby, she asks that they cut off the flower head and bring it into the Tri-River Area Extension office at 2775 U.S. Highway 50 to be identified. If it is purple loosestrife, the county can help get rid of it.
“If we can get people looking for purple loosestrife, then we can prevent it from becoming a bigger problem,” Werkmeister said.