Tip of the Mitt Watershed Council
Loading
Skip Navigation LinksHome > Learn > Aquatic Invasive Species > Phragmites

Phragmites

Phragmites (Phragmites australis), also known as the common reed, is an aggressive wetland invader that grows along the shorelines of water bodies or in water several feet deep. It is characterized by its towering height of up to 14 feet and its stiff wide leaves and hollow stem. Its feathery and drooping inflorescences (clusters of tiny flowers) are purplish when flowering and turn whitish, grayish, or brownish in fruit. Eventually, Phragmites become the sole dominant plant in many of these wetlands at the expense of native flora and animals dependent on these native habitats.

The Problem

Common reed has been invading aggressively much of the Great Lakes shoreline as well as inland wetlands. Once Phragmites invades a site it quickly can take over a marsh community, crowding out native plants, changing marsh hydrology, altering wildlife habitat, and increasing fire potential. Its high biomass blocks light to other plants and occupies all the growing space below ground so plant communities can turn into a Phragmites monoculture very quickly. Phragmites can spread both by seed dispersal and by vegetative spread via fragments of rhizomes that break off and are transported elsewhere. New populations of the introduced type may appear sparse for the first few years of growth but due to the plant’s rapid growth rate, they will typically form a pure stand that chokes out other vegetation very quickly.

Identifying the Problem

Before taking any action, you should first determine whether the plants are native or invasive Phragmites. Use the following photos to help you identify the difference between native and introduced species of Phragmites.

Photos courtesy: Michigan Sea Grant


Click here to download a pdf of the "How to Identify Phragmites in Northern Michigan" worksheet.

Management Techniques

Once a problem stand of Phragmites has been identified, one or more techniques may be applied to control it. Areas with large, established, populations of Phragmites are best restored using herbicides. Other options include prescribed burning, hydrologic controls, and removal.

Landowners should follow the recommended control methods that include herbicide treatment followed by removal of the invasive plants and annual maintenance, as outlined in the publication Guide to Control and Management of Invasive Phragmites.

Biological

At this time no means of biological control are available in the United States for treating Phragmites infestations.

Chemical

Glyphosate-based herbicides (e.g., Rodeo®) are the most effective control method for established populations. Rodeo, a nonselective herbicide, kills all grasses and broad-leaved emergents. It degrades quickly into natural products, so it is virtually non-toxic to aquatic animals. If a population can be controlled soon after it has established chances of success are much higher because the below-ground rhizome network will not be as extensive. Small stands can be treated by injecting stems, hand swiping, or selectively spraying with backpack sprayers. Large stands require more substantial equipment and can include a helicopter. Herbicides are best applied in late summer/early fall after the plant has flowered either as a cut stump treatment or as a foliar spray. It is often necessary to do repeated treatments for several years to prevent any surviving rhizomes from resprouting. When applying herbicides in or around water or wetlands, be sure to use products labeled for that purpose to avoid harm to aquatic organisms.

Permits are required from the Michigan Department of Environmental Quality for chemical treatments. For chemical treatment information including permitting requirements and blank permit application forms visit www.michigan.gov/deqinlandlakes (Select Aquatic Nuisance Control) or contact the Aquatic Nuisance Control Program.

The use of a licensed applicator who is certified in aquatic pest management is recommended for herbicide application, especially in large, dense stands and in sensitive areas such as wetlands: Pesticide Application Businesses Licensed by the State of Michigan.

Burning

Prescribed burning after the plant has flowered, either alone or in combination with herbicide treatment, may also be effective. Burning after herbicide treatment also reduces standing dead stem and litter biomass which may help to encourage germination of native plants in the following growing season. Plants should not be burned in the spring or summer before flowering as this may stimulate growth. Prescribed burning does not require a permit from the State of Michigan, but often does require approval from the local unit of government.

Mechanical

Not successful in eradicating common reed, but is useful to eliminate the fire hazard potential. Cutting any grass at the wrong time may stimulate growth and increase stem density. Cutting at the end of the growing season or in winter can increase density. Removal of Phragmites through digging and hand pulling is also ineffective due to the extensive root system created by this plant. Disturbing the soil through mechanized disking or raking may also contribute to rapid expansion of Phragmites and is not recommended. Mechanical removal of dead plant material can be beneficial in larger stands for better growing conditions for native plants. However, this can also promote the growth of any Phragmites plants that were not affected by herbicide treatment.

A permit from the U.S. Army Corps of Engineers is required for most activities that alter the Great Lakes coastal areas, including removal of vegetation. U.S. Army Corps of Engineers Regulatory Staff: (313) 226-2218 http://www.lre.usace.army.mil/Missions/RegulatoryProgramandPermits/ApplyforAPermit.aspx

A permit is needed from the Michigan Department of Environmental Quality for removal of live Phragmites. Removal of wetland vegetation requires an individual permit from the Water Resources Division. Michigan Department of Environmental Quality Water Resources Division: (517) 373-1170 www.michigan.gov/jointpermit

Flooding

Flooding can control common reed if rhizome is covered with water for four months during the growing season. It is important to ensure that flooding reaches all affected marsh areas for this period.
Tip of the Mitt Watershed Council • 426 Bay Street, Petoskey, MI 49770
PH: (231) 347-1181 • Fax: (231) 347-5928 • www.watershedcouncil.org
Copyright © 2014 by Tip of the Mitt Watershed Council. All rights reserved. SiteMap
Powered by SiteChalk