MENOMONIE — The pleasing-to-the-eye purple flowers popping up alongside state roadways this spring may not be as desirable upon closer inspection.
Dames rocket, a restricted invasive species according to Wisconsin’s NR40 Invasive Rule, resembles the native plant wood phlox, and if it isn’t contained, can crowd out the native plant.
According to the Wisconsin Department of Natural Resources, dames rocket is thought by many to be a native wildflower and, until its inclusion in the NR40 invasive list, was found in wildflower seed mixes and planted as an ornamental. It quickly escapes cultivation because of its prolific seed set.
“It can outcompete native plants and take over an area,” said Christopher Gaetzke, executive director of the Lower Chippewa Invasives Partnership, a nonprofit organization working to increase invasive species awareness and control. “People like how it looks and they don’t know what they have, so they don’t cut it.”
Dames rocket is a showy, short-lived perennial or biennial, according to the DNR. It invades moist and moderately moist woodlands, woodland edges, roadsides and open areas.
Dames rocket can be purple or white and have four petals and are 2 to 3 feet tall. Wood phlox has five petals and is purple.
“It’s becoming as common as garlic mustard,” Gaetzke said. “It out-competes the native plants.”
Gaetzke said dames rocket is just one of about 35 invasive plants the Lower Chippewa Invasives Partnership has identified in western Wisconsin.
LCIP has identified leafy spurge, wild parsnip, common buckthorn, Japanese knotweed, garlic mustard and spotted knapweed as six target invasives because they are the most common in the area, he said.
“It’s important to get information out there, especially for landowners who might not know what they have growing on their property,” Gaetzke said. “From that awareness usually comes projects to control the invasive plants.”
The goal of the Lower Chippewa Invasives Partnership is to control invasive plants through partner cooperation and community action. LCIP works with conservation and environmental organizations with similar goals and uses funding from local, state and federal sources to complete projects.
“We’re probably not going to get rid of these plants,” Gaetzke said, “but we can control them in areas that are especially important to the public.”
The group works with Chippewa, Dunn, Eau Claire, Pepin St. Croix and Pierce county highway departments and towns to slow the spread of wild chervil, wild parsnip, spotted knapweed and phragmites.
Gaetzke said concern about the spread of wild parsnip and the partnership between LCIP and St. Croix County led to the county treating about 50 percent of its roadways for the plant. When sap from the wild parsnip comes in contact with skin in the presence of sunlight, it can cause severe rashes, blisters and discoloration of the skin.
“I’ve seen it get on faces, eyebrows, in people’s mouth,” Gaetzke said. “In the sun, it can actually make the skin turn black. It’s a pretty nasty plant.”
During a June 13 field day with the statewide Invasive Plants Association of Wisconsin, the groups found 18 invasive plants on an 11-mile bus ride around Menomonie. Gaetzke said the groups found 17 invasive plants within two miles of the city.
“That’s pretty common around more populated areas,” he said. “The farther you get from urban areas, the fewer invasive plants you tend to find.”
LCIP is planning a similar tour in July in Eau Claire, where the group has uncovered 17 invasives in Putnam Park, a state natural area near downtown.
Gaetzke said landowners concerned about potential invasive plant problems can contact the Lower Chippewa Invasives Partnership to set up a site assessment or help create a control plan. He can be reached at 715-539-2766 or firstname.lastname@example.org. Gaetzke said more information can be found at the LCIP office, 700 Wolske Bay Road, Suite 275, Menomonie, but he recommended calling first to make sure the office is open.
For more information about the Lower Chippewa Invasives Partnership, visit https://lcinvasives.org.