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FACT SHEET: GIANT REED

Common Reed 

Phragmites australis (Cav.) Trin. ex Steud.

Grass family (Poaceae) 

NATIVE RANGE 

Eurasia 

DESCRIPTION 

Common reed, or Phragmites, is a tall, perennial grass that can grow to over 

15 feet in height. In North America, both native phragmites (Phragmites 

australis ssp. americanus Saltonstall, P.M. Peterson & Soreng) and introduced 

subspecies are found. Introduced Phragmites forms dense stands which 

include both live stems and standing dead stems from previous year’s growth. 

Leaves are elongate and typically 1-1.5 inches wide at their widest point. 

Flowers form bushy panicles in late July and August and are usually purple or 

golden in color. As seeds mature, the panicles begin to look “fluffy” due to the 

hairs on the seeds and they take on a grey sheen. Below ground, Phragmites 

forms a dense network of roots and rhizomes which can go down several feet 

in depth. The plant spreads horizontally by sending out rhizome runners which 

can grow 10 or more feet in a single growing season if conditions are optimal. 

Please see the table below for information on distinguishing betweeen native 

and introduced Phragmites. 

ECOLOGICAL THREAT 

Once introduced 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 belowground 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. 

DISTRIBUTION IN THE UNITED STATES 

Phragmites occurs throughout the lower 48 states and southern Canada. It has 

been reported to be invasive in natural areas in 18 states including Colorado, 

Connecticut, Delaware, Georgia, Indiana, Kentucky, Maryland, Michigan, North 

Carolina, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, 

Tennessee, Virginia, Vermont, and Wisconsin, and the District of Columbia. 

HABITAT IN THE UNITED STATES 

Tidal and nontidal brackish and freshwater marshes, river edges, shores of 

lakes and ponds, roadsides, disturbed areas. 

BACKGROUND 

Preserved remains of native Phragmites that are 40,000 years old have been found in the southwest indicating that it is a 

part of the native flora of that region. In coastal areas, preserved rhizome fragments dating back 3000-4000 years have 

also been found in salt marsh sediments indicating that it is also native to these habitats. Native American uses of 

Phragmites include use of stems for arrow shafts, musical instruments, ceremonial objects, cigarettes, and both leaves 

and stems for constructing mats. 
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Introduced Phragmites is thought to have arrived in North America accidentally, most likely in ballast material in the late 

18th or early 19th centuries. It established itself along the Atlantic coast and over the course of the 20th century, spread 

across the continent. In Europe Phragmites is grown commercially and is used for thatching, fodder for livestock, and 

cellulose production. It is also declining in parts of Europe which has been of concern to natural resource managers there. 

Here in the United States it is not used for many purposes. 

BIOLOGY & SPREAD 

While each Phragmites plant may produce thousands of seeds annually, seed viability is typically low although there 

appears to be a great deal of interannual variation in fecundity. Dispersal to new sites is typically by seed except along 

rivers and shorelines where fragments of rhizomes may be washed down to new sites where they can establish. Along 

roadsides, rhizomes fragments may also be transported by heavy machinery between sites. At this time, there is no 

evidence for hybrid native/introduced populations occurring in the field. 

MANAGEMENT OPTIONS 

Areas with large, established, populations of Phragmites are best restored using herbicides. Other options include mowing 

and prescribed burning. 

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. 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. 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. 

Fire 

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. 

Mechanical 

This type of control (e.g., repeated mowing) may be effective at slowing the spread of established stands but is unlikely to 

kill the plant. Excavation of sediments may also be effective at control but if small fragments of root are left in the soil, they 

may lead to reestablishment. 

USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all 

recommended personal protective gear and clothing. Contact your state department of agriculture for any additional pesticide use 

requirements, restrictions or recommendations. 

NOTICE: mention of pesticide products on this page does not constitute endorsement of any material.

CONTACTS 

For more information on identification and control of Phragmites, contact: 

• Dr. Kristin Saltonstall, Adjunct Research Scientist, Horn Point Laboratory, University of Maryland Center for 

Environmental Science, (914) 526-2498, ksalton at hpl.umces.edu 

SUGGESTED ALTERNATIVE PLANTS 

Native plant species that are adapted to local conditions should be used in restoration projects and as a substitute for 

Phragmites erosion control practices. 
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How to Distinguish Native and Introduced Phragmites plants: 

It can be difficult to definitively distinguish native from introduced Phragmites plants without genetic testing due to the 

plasticity of the species and its ability to adapt to a wide range of conditions. However, a number of morphological 

characteristics have now been identified that can be used to determine a population’s type. These characters can be 

subtle (e.g. color variation) and subjective making positive identification difficult. Given this, an assignment of native or 

introduced status to a population should not be made unless several characters clearly match the patterns shown in table 

1. 

Table 1: Morphological characters useful in distinguishing Native and Introduced Phragmites populations.* 

CHARACTER 

Photo 

NATIVE INTRODUCED 

Ligule width** 1.0-1.7 mm 0.4-0.9 mm 

Lower glume length 3.0-6.5 mm 2.5-5.0 mm 

Upper glume length 5.5-11.0 mm 4.5-7.5 mm 

Adherence of leaf sheaths** Loose – both leaves and leaf 

sheaths are usually dropped as 

the plant senesces 

Tight – leaves may drop off but 

leaf sheaths typically adhere 

tightly to dead stems 
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CHARACTER 

Photo 

NATIVE INTRODUCED 

Stem color (look under the leaf sheaths, 

especially in places where the stem is exposed 

to sunlight) 

Summer – green to maroon, may 

have maroon color at the nodes 

only 

Winter – yellow to brown 

Summer – typically all green with 

yellowish nodes although some 

lower nodes may have maroon 

color 

Winter – yellow 

Stem spots Small round fungal spots MAY be 

present in late summer and on 

dead stems 

Extremely rare. Patches of black 

filamentous fungi may be seen 

Stem density May occur as a monoculture, 

often co-occurs with other plant 

species 

Typically grows as a monoculture, 

young newly established 

populations and those in areas of 

high salinity may be less dense 
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CHARACTER 

Photo 

NATIVE INTRODUCED 

Leaf color Yellow-green – usually lighter 

than introduced 

Blue-green in most habitats but 

may be yellow-green in brackish 

habitats 

Habitat Undisturbed sites 

MidAtlantic – fresh to oligohaline 

tidal marshes 

Midwest – fens, marshes 

Highly disturbed to undisturbed 

sites, dominates brackish 

marshes along the Atlantic coast, 

common along roadsides 

throughout the U.S. 

* This table should not be used to distinguish between Phragmites populations along the Gulf Coast where another type of 

Phragmites, the Gulf Coast type, which looks similar to introduced Phragmites, is also found. 

** Most reliable characters distinguishing native from introduced Phragmites. 

OTHER LINKS 

• http://www.invasive.org/search/action.cfm?q=Phragmites%20australis 

• http://nbii-nin.ciesin.columbia.edu/ipane/icat/browse.do?specieId=85 

• http://www.nps.gov/plants/alien/fact/pdf/phau1-powerpoint.pdf

AUTHOR 

Dr. Kristin Saltonstall, Adjunct Research Scientist, Horn Point Laboratory University of Maryland Center for Environmental 

Science, Solomon, MD 

EDITOR 

Jil M. Swearingen, National Park Service, Center for Urban Ecology, Washington, DC 

PHOTOGRAPHS 

Jil M. Swearingen, National Park Service, Center for Urban Ecology, Washington, DC 

Dr. Kristin Saltonstall, Adjunct Research Scientist, Horn Point Laboratory University of Maryland Center for Environmental 

Science, Solomon, MD 

Robert Meadows, Environmental Scientist, North DE Wetland Rehabilitation Program, DE Mosquito Control Section, 

Newark, DE 

REFERENCES 

Chambers, R.M., L.A. Meyerson, and K. Saltonstall. 1999. Expansion of Phragmites australis into tidal wetlands of North 

America. Aquatic Botany 64: 261-273. 
20 May 2005 Page 6 of 6 

Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

http://www.nps.gov/plants/alien/

Marks, M., B. Lapin, et al. 1994. Phragmites australis (P. communis): Threats, management, and monitoring. Natural 

Areas Journal 14: 285-294. 

Meyerson, L.A., K. Saltonstall, L. Windham, E. Kiviat, and S. Findlay. 2000. A comparison of Phragmites australis in 

freshwater and brackish marsh environments in North America. Wetlands Ecology and Management 8: 89-103. 

Norris, L., J. E. Perry, and K.J. Havens. 2002. A summary of methods for controlling Phragmites australis. Virginia 

Institute of marine Science Wetlands Program Technical Report No. 02-2. 

Saltonstall, K. 2002. Cryptic invasion of a non-native genotype of the common reed, Phragmites australis, into North 

America. Proceedings of the National Academy of Sciences USA 99(4): 2445-2449. 

Saltonstall, K. 2003. Microsatellite variation within and among North American lineages of Phragmites australis. Molecular 

Ecology 12(7): 1689-1702. 

Saltonstall, K. 2003. Genetic variation among North American populations of Phragmites australis: implications for 

management. Estuaries 26(2B):445-452. 

Saltonstall, K. 2003. A rapid method for identifying the origin of North American Phragmites populations using RFLP 

analysis. Wetlands 23(4) 1043-1047. 

Saltonstall, K., P.M. Peterson, and R. Soreng. 2004. Recognition of Phragmites australis subsp. americanus (Poaceae: 

Arundinoideae) in North America: evidence from morphological and genetic analyses. Sida. 

Swearingen, J. 2009. WeedUS Database of Plants Invading Natural Areas in the United States: Common Reed 

(Phragmites australis). http://www.invasive.org/weedus/subject.html?sub=3062. 

USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 

70874-4490 USA.