Introduced Species Summary Project
 Common Reed

(Phragmites australis (Cav.) Trin. Ex Steud)

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Common Name: Common reed

Scientific Name: Phragmites australis (Cav.) Trin. Ex Steud


Phylum or Division: Angiosperm
Class: Monocot
Family: Poaceae

Identification: The common reed is a tall perennial grass with an approximate height of 15 feet or more and forms dense stands with about 19 steams per square foot both dead and alive. It has horizontal stems (Rhizomes), which annually send out stiff vertical shoots that are stiff and have sheath like leaves. The shoots and leaves are stiff and sharp due to high amounts of cellulose and silica. The flower stem is about one foot long with many feathery branches. Each individual flower is about 1/2 an inch in length. Common reed can sprout from rhizomes or seeds and some colonies can be hundreds of acres in size.

Phragmites tends to prefer sunny wetlands and is also found in areas of moist soil in fresh or brackish water marshes. It can be found along riverbanks and lakeshores. It grows in areas of disturbed soil, ditches, roadsides, and other areas of degradation. The only thing limiting its growth is high salinity. It is interesting to note that while Phragmites is a native plant to the United States what has made it so invasive is that it finds a niche in any disturbed area, and can easily out compete any other species vying to reestablish it self in the same disturbed area.

Original Distribution: Phragmites is native to the Americas

Current Distribution: Canada to South America only in greater abundance.

Site and Date of Introduction: Phragmites is native to North America therefore there is no specific introduction site or date. Phragmites occurs any place humans have disturbed or degraded the topsoil or environment in an area with favorable growing conditions. There are currently studies being done on the possibility that in the early 20th century a more genetically aggressive strain of Phragmites came in from abroad.

Mode(s) of Introduction: Phragmites is a prolific seed spreader and soil movement easily deposits its rhizomes, by soil moving equipment, animals, water, or happenstance.

Reason(s) Why it has Become Established: Phragmites is one of the most opportunistic organisms in the western hemisphere. Any disturbed area with favorable growing conditions will support it. Phragmites can easily takeover an area when there is environmental stress, such as altered hydrology, restricted tidal flooding, storm drainage ditches, storm water discharges, road salt and water pollution. These factors have helped Phragmites to establish itself in nonnative niches.

Ecological Role: Phragmites produces beautiful stands and are valuable to wild animals such as nesting ducks, herron and egrets. Phragmites also provides good cover for deer. Phragmites provides good forage when stalks are still young and tender and birds feed on their seeds. Phragmites generally is monodominant but occasionally is found with bulrush, cattail, arrowhead, northern redgrass and sedge.

Benefit(s): Soil stabilization, revegitation projects, control of shoreline erosion, stabilization of stream, river and canal banks, grazing, thatching, cellulose source for paper and textile manufacturing are just some of the benefits of Phragmites.

Threat(s): That Phragmites contributes to the reduction of biodiversity in wetlands is the primary threat. Invasive stands of Phragmites can quickly replace other native species such as short grasses, cattails and other native plants. Phragmites also affects marsh habitat of birds and fish and can create a fire hazard when there is a large amount of dead biomass.

Control Level Diagnosis:  Medium priority should be applied to the control of Phragmites. But this is not to say that this is not a serious problem in fact, Phragmites if not controlled will rapidly change the complexion of the environment and contribute to the reduction in biodiversity in the niches they takeover and thus, should be taken seriously.

Control Method: Phragmites can be controlled through many different methods, but the problem is there are money, timing and pollution constraints that affect these programs.1) The easiest way to control a portion of the Phragmites problem is to eliminate restrictive flows in saltmarshes, increased salinity from this method kills Phragmites. 2) Cutting, mowing or disking can help the problem. If mowing is done too late or early it can actually stimulate growth and make denser stands. This method does contribute to a reduction in fire hazard. Disking is too costly but can work on a small-scale basis. 3) Herbicides, while they do work, pose another type of environmental problem killing other grass species and it is also expensive. 4) Burning can only work if it is a root burn and burning can actually stimulate growth. 4) Covering with plastic after mowing can have good results after a few days because of higher temperatures generated under the plastic. This method is labor intensive. 5) A combination of all these methods along with aggressive replanting of other native species is the most effective way to inhibit encroachment by Phragmites.


Massachusetts Audubon Society: Saltmarsh Science Project

Phragmites: Controlling the All-Too-Common Common Reed, Wetlands Restoration & Banking Program, Massachusetts Executive Office of Environmental Affairs, Tinner 1995

Phragmites australis, Ronald J. Uchytil  1992

Invasive Plant Council of the State of New York (IPC), Common Reed - Phragmites australis, April 13, 2001

Picture(s) may be obtained at

Author: David Blinken
Last Edited: 03/07/02

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Project Editor: James A. Danoff-Burg, Columbia University