Herbicide, mowing among treatments to fight invasive phragmites

By: K. Michelle Moran | Grosse Pointe Times | Published December 5, 2012

GROSSE POINTE SHORES — It may seem like a losing battle, but state officials are hoping that new regulations will better enable residents to fight back against phragmites, the invasive weeds that have overtaken shorelines and crowded out native plants.

Residents from across the state packed an informational forum Nov. 26 at Shores City Hall that featured officials from the Michigan Department of Environmental Quality discussing ways to control phragmites, which have become common not only along Lake St. Clair, but on other waterways throughout the state. The program was organized by outgoing State Rep. Tim Bledsoe, D-Grosse Pointe City.

Although federal permits from the U.S. Army Corps of Engineers are still required and people still need state permits, as well, for activities such as spraying herbicide, mowing and some other activities that used to require minor permits can now be done without state approval, said Andrew J. Hartz, district supervisor for the MDEQ.

There is a native species of phragmites, but the tall wetlands grass that people most commonly see these days in Michigan is the invasive variety, which is native to Europe. Hartz said the plant is wreaking havoc on coastal wetlands that support fish spawning and provide vital wildlife habitat. He said phragmites are also choking out native plants, like cattails and bulrushes.

“If you’re here, you know that phragmites is a serious problem,” Hartz told attendees.

Legislation passed this summer is the reason for the permitting changes. The state bill enabling residents to take certain steps against phragmites without needing a permit initially excluded the Lake St. Clair shoreline, but Bledsoe said he successfully pushed to get it included.

“We’ve at least reduced, to some degree, the hurdles to eliminating these invasive phragmites,” Bledsoe said.

State officials say initial spraying and follow-up spot treatments with herbicides are needed to get phragmites under control and allow for the reintroduction of native plants.

Spraying chemicals “is our only effective treatment at this point,” said Todd Losee, a wetlands specialist with the MDEQ.

A chemical treatment in the late summer or early fall — preferably applied by a professional — is one of the first steps that can be taken to fight phragmites, he said. Treating at that time of year enables the chemical to be pulled into the plant’s root system, where it will do the most damage. Losee said the two chemicals that seem to work are Glyphosate and Imazapyr, but he cautioned that the latter “will kill everything, and it will kill everything for a long time.” Chemical treatment should be done before the first hard frost, he said. The beginning of September is ideal, Losee said. After about two weeks, residents should see the plants turn brown. If there’s any green remaining after that time, he said those individual plants can be sprayed, with spot treatment to be done about once every two weeks during this first phase of herbicide application.

Mowing can then be done in the winter, he said. But Losee cautioned that a regular lawnmower won’t work on the thick, strong plant, so people need more powerful cutting equipment. Mowing without chemical treatment is a bad idea, because it “creates a stronger root system,” Losee said.

A prescribed burn would be the next step, said Losee, but this is something that should only be undertaken by professionals, because such a blaze can easily spread if not handled properly. The controlled burn not only gets rid of some of the phragmites, but it also increases the amount of sunlight that reaches the affected area, stimulating the growth of native plants, Losee said. Planting of a native meadow mix is one way residents could get a return of other plants, which are lower-growing and won’t have the negative impact on the environment, recreation and property values that phragmites have caused.

Losee said targeted spot applications of herbicide will be necessary after the main batch of phragmites has been eliminated, to get rid of remaining plants and keep them from coming back.

Unfortunately, this is a battle that residents will likely still be fighting even after they seem to have gotten the phragmites under control. Losee said there are no native plants strong enough to crowd out phragmites and keep the invasive grass from coming back.

“You still have to stay on top of phragmites,” he said.

One of the best ways for people to avoid having problems with invasive species is to not bring plants from other states or countries to Michigan in the first place. Losee said many of the invasive plants environmental experts are now battling were inadvertently introduced by well-meaning people who brought plants up from the south or shared cuttings with their neighbors, not realizing these species could spread and cause problems for the local ecosystem.

Residents are asked to watch for other invasive plants that have been spotted in the state as well, and report any sightings to the Great Lakes Early Detection Network at www.gledn.org. The Midwest Invasive Plant Network has a flyer with photos of invasive plants to watch for; the link is www.mipn. org/MIPN_Terrestrial_Flyer_2012_high res.pdf.

At press time, Losee said a team of experts from the Aquatic Invasive Species Council was likely to have the latest recommendations about phragmites in the next three or four months. A phragmites collective has been created to be a single source of information for anyone seeking additional data about this plant. For more details, visit www.greatlakesphragmites.net.

For more about state rules and advice with regard to phragmites, visit www.michigan.gov/deq.