Invasive Phragmites Australis: Learning the basics

Find out more about this invader and how it spreads.

A large dense stand of invasive phragmites is shown along a waters edge.
Invasive phragmites can develop into dense monocultures reducing viable habitat, limiting recreation opportunities, and posing safety concerns.

National Invasive Species Awareness Week is Feb. 25-March 3, 2019. The goal is to draw attention to invasive species and what individuals can do to stop the spread and introduction of them. This effort is sponsored by a diverse set of partners from across the country. To increase awareness of the issues, Michigan State University Extension and Michigan Sea Grant are publishing articles featuring resources and programs in our state working on invasive species issues.

In the Saginaw Bay region of Michigan, many partners are collaborating to stop the spread of invasive phragmites. For instance, students at Au Gres-Sims School District study the density of invasive phragmites while also evaluating the impact of treatment measures lead by Huron Pines on Big Charity Island, part of Michigan Islands National Wildlife Refuge (MINWR). Support for this project was provided by U.S. Fish and Wildlife Service Michigan Islands National Wildlife Refuge and through partners participating in the Northeast Michigan Great Lakes Stewardship Initiative (NEMIGLSI) network. Funding and technical support for this restoration was provided by the U.S. Fish and Wildlife Service’s Coastal Program

The Saginaw Bay CISMA (Cooperative Invasive Species Management Area) has also supported phragmites control and management efforts in the Saginaw Bay watershed. Since 2015, the strike team and partners have treated over 100 sites across 150 acres. In 2018, one of the collaborative partners, Arenac Conservation District, worked with landowners to provide technical assistance for plant treatment, and they partnered with the City of Au Gres to treat invasive phragmites on the newly acquired Au Gres Harbor Site, which was deeded over by Michigan’s Department of Natural Resources.

As the Great Lakes Phragmites Collaborative notes, invasive phragmites impact many lives across the Great Lakes basin. They develop into dense monocultures, which do not serve as nesting habitat for marsh bird species. These dense stands of phragmites can also limit access to water for recreation, block views, and pose safety concerns.

Phragmites facts

  • Species name: non-native Phragmites (Phragmites Australis subsp. australis)
  • Description: Invasive phragmites can develop in dense monocultures. The plant can grow to be 15 feet tall with many stems in a small area (up to 60 stems per square foot). Check out this Phragmites Basics page developed by the Great Lakes Phragmites Collaborative for even more information.
  • Similar species: native Phragmites (Phragmites australis subsp. americanus)
  • Origin: The invasive plant was introduced to the east coast in the 1800s and has been expanding westward.
  • Extent of range: According to the Great Lakes Phragmites Collaborative, invasive phragmitis is now found in the contiguous United States (all 48 states) and all of the Canadian provinces.
  • How it is spread: Invasive phragmites can spread in three different ways: seed dispersal (for spreading to new areas), stolons (for spreading in established areas), and rhizomes (for spreading in established areas). Each seed head can produce up to 2,000 seeds, which helps the plant spread to new areas. Stolons are horizontal stems which help the plant to spread and can grow +50 feet during a season. These stems are often red and can cause confusion with native phragmites. Rhizomes are underground stems, which can sprout and help the parent plant to spread. Early detection and management are important to stop the development of these underground networks.
  • Management actions/options: Herbicide is the recommended initial treatment technique, and it is best to pair it with other non-chemical control methods (e.g. cutting or mowing) to further stress the plant. Treatment is most effective when the invasive phragmites is detected early. Well-established phragmites can still be managed, but requires a greater investment of resources including both time and money.  Learn more about control and management efforts in this guide developed by Michigan Department of Environmental Quality and partners

Help prevent the spread

Learn how to recognize the difference between native or invasive phragmites, and contact your local conservation district for information about treatment measures available locally. Invasive phragmites most resembles native phragmites when it is first introduced to a new area. It important to learn how to detect the difference between the two plants for early detection and management. This guide from Michigan Natural Features Inventory shows how to spot the difference.

Michigan Sea Grant helps to foster economic growth and protect Michigan’s coastal, Great Lakes resources through education, research and outreach. A collaborative effort of the University of Michigan and Michigan State University and its MSU Extension, Michigan Sea Grant is part of the NOAA-National Sea Grant network of 33 university-based programs.

This article was prepared by Michigan Sea Grant Extension educator Meaghan Gass under award NA14OAR4170070 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce through the Regents of the University of Michigan. The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration, the Department of Commerce, or the Regents of the University of Michigan.


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