Throughout the Great Lakes region, a very tall, densely growing grass known as Phragmites australis or common reed grass is beginning to settle in Wisconsin’s roadsides, wetlands and lake shorelines. Wisconsin has long had a native strain of Phragmites, which is usually innocuous and should be protected in most places. However, in recent years, a more aggressive, non-native variety has moved westward across the United States. Over the last few years, a great deal of work has been done to control large patches of the invasive strain of this species, particularly on the shores of Lake Michigan and Green Bay.
In 2013, DNR received $200,000 from the US Fish and Wildlife Service’s Great Lakes Restoration Initiative fund to implement a new non-native Phragmites control project within Wisconsin’s Lake Michigan basin. The purpose of this project is to find the leading western edge of the non-native Phragmites invasion and “push” it back toward Lake Michigan. In many Wisconsin counties, especially in the western Lake Michigan basin, the non-native strain is a newly establishing invasive wetland plant. Efforts to prevent this establishment and spread within the Lake Michigan basin will help prevent many of our inland lakes and wetlands from encountering the problems this plant has caused on our Great Lakes shorelines.
A previous GLRI funded project conducted by the department, which worked to eradicate over 3,300 acres of non-native Phragmites and non-native Lyme grass (Leymus arenarius) on west Green Bay and Lake Michigan shorelines, had tremendous success. Treated areas had over a 90 percent success rate after two years of treatment. DNR’s new Phragmites control project is predicted to have as much or more success at eliminating non-native Phragmites as DNR will be treating much smaller sites with less established plants.
Invasive Phragmites often crowds out native plants and can grow as tall as 15 feet, resulting in blocked shoreline views and reduced access to swimming and fishing areas. Phragmites patches expand via underground rhizomes and above ground runners or stolons, and spread quickly to new areas by contaminated soil (with rhizome pieces), stem fragments (e.g., from mowing), and by seeds that germinate readily in disturbed ground or exposed lakebeds.
This project targets eliminating newly establishing invasive Phragmites infestations in areas such as wetlands, lakeshores, road rights-of-way, State Natural Areas, parks and adjoining private lands. It will focus first on non-native Phragmites in those counties in the far northwestern part of the Lake Michigan basin, then expand south, starting with the counties along the western edge of the basin, as funding allows. Other criteria, such as the availability of partner organizations, prior control work done, and the existence of rare species will guide treatment site selection.
The goal of DNR’s new Phragmites control project is to treat at least 200 acres of non-native Phragmites, beginning in late summer 2014, with follow-up treatments in 2015. DNR is reaching out to partners that may have location data in order to build a map of non-native Phragmites populations across the state that will guide control activities for this project.
Control treatments of Phragmites patches are most effective if all parts of an infestation are treated, which means that getting all landowners of a site to agree to treatment is important for success. Aquatic formulas of herbicides, especially imazapyr, are commonly used because Phragmites is a resilient species and may not be well controlled with other methods. The best way to control Phragmites is to catch it early before it becomes well-established. That is where local and state natural resource managers need your help!
This project is actively seeking reports of non-native Phragmites, which can be sent to DNR in a number of ways. Learn how to distinguish native from non-native, then report all non-native sightings on our wetland invasive reporting website. Reports of non-native Phragmites are compiled in a GIS program and will be used to plan treatment areas. A great online resource to learn a lot more about this invasive plant, and ways to control it, is found at the Great Lakes Phragmites Collaborative website. Don’t forget to check out the DNR’s invasive species website to learn about other invasives found in our lakes, rivers, wetlands and upland environments and ways in which you can help prevent their spread!