Common Reed

Fact SheetPhragmites australis

Identification

Appearance

Phragmites australis is a tall, perennial grass that can grow to heights of 15 feet or more. Broad, pointed leaves arise from thick, vertical stalks.

Foliage

Leaves are 6-23.6 inches long, 0.4-2.4 inches wide, flat and glabrous.

Flowers

The flower heads are dense, fluffy, gray or purple in color and 5.9-15.7 inches long. Flowering occurs from July to October.

Fruit

The seeds are brown, light weight, and about 0.3 inches long. In the fall the plant turns brown, and the inflorescences persist throughout the winter.

Biology

Origin

Native to Eurasia and Africa.

Habitat

Disturbed habitats, brackish or salt marshes and flats, fens, fresh tidal marshes or flats, marshes, shores of rivers or lakes, wetland edges.

Life Cycle

Reproduction is thought to take place mainly through vegetative means via rhizome and stolon fragments. Rhizomes spread horizontally during the growing season. New stalks shoot in spring, and flowers appear in late June with bushy panicles. Seeds form by August to early fall and are dispersed between November and January. Following seed set, nutrients are translocated down into the rhizomes and the above-ground portions of the plants die back for the season. Water depths of more than 5cm and salinities above 20ppt (2%) prevent germination. Percentage of germination increases with increasing temperature from 16 to 25˚C while the time required to germinate decreases from 25 to 10 days over the same temperature range.

Ecological Threat

Common reed replaces native grasses, sedges, and herbaceous plants. It provides poor quality habitat for insects, birds and amphibians. Fish populations that reproduce in wetlands and marshes inundated with phragmites suffer higher egg and juvenile mortality. The plant also exudes allelopathic compounds from its roots, causing root death of nearby native plants.

Management Options

Treatment Concerns: 

  • Removing mat of dead phragmites canes can assist in the growth of desirable vegetation by allowing sunlight to reach the soil surface. 

General Guidance:

  • Most methodologies alone will not suffice and should be part of an integrated pest management plan.  
  • Which methods you choose also depend on the purpose of control: eradication (removal of all plants, plant parts, and seed bank), or containment (reducing seed production, reducing spread, reducing growth, removing individual plants near site of concern).  
  • All action promotes disturbance - mechanical, chemical, and even just doing nothing. Our work is in figuring out how to minimize disturbance and maximize positive benefits. 
  • The intent of mechanical or chemical treatment is to kill target plants. 
  • Management options listed below are representative of research by institutions like The Nature Conservancy, the Great Lakes Phragmites Collaborative, Michigan Department of Environmental Quality, and the US Fish and Wildlife Service. 
  • Here are additional guidance documents on best management practices for Phragmites/common reed. 
  • Great Lakes Phragmites Collaborative 
  • US Fish and Wildlife Service Phrag Book 
Summary of Mechanical Treatment Options
  • Mechanical treatment at any scale can increase the efficacy of other management actions by removing dead stems and increasing access for future management at the site 
  • Mechanical removal can throughout the year. These methods can be used in the dormant period to clear dead and senesced Phragmites for future management at the site.  
  • Mechanical cutting and removal of Phragmites before seed heads mature may prevent unwanted spread, but cutting the stalks above ground level without other treatment may stimulate growth. 
  • Mechanical treatment can sometimes cause greater disturbance than if the site was left alone or if another treatment option was utilized. 
  • If pulling or digging, remember that soil disturbance can encourage growth from seed bank.    

text in a table describing mechanical treatments for Phragmites

Summary of Chemical Treatment Options
  • Removing dead stems may allow for increased herbicide contact with the living Phragmites tissues when herbicide is applied, and can allow for easy spot treatment of new shoots in the spring and early summer. 
  • Be careful not to damage or kill nearby desirable plants when conducting management work.  
  • Always read and follow pesticide label directions. Application of pesticides may require a certification from the Agency of Agriculture, Food and Markets. The Agency website provides information on what applicator certification is needed.
  • If a treatment for a specific species isn’t listed on a given product, don’t use it. 
  • Product labels may require you to check Endangered Species Protection Bulletins. Learn more about protection bulletins here.  
  • Understand the risk of, and how to avoid, drift.  
  • The timing of some chemical treatments may overlap with when certain plants are flowering, and, in order to protect pollinators, herbicides should not be applied when plants are flowering. To mitigate the risk, consider utilizing an integrated pest management plan, such as cutting the plants to set back flowering time, and then applying pesticides in the lowest effective volume. 
  • Chemical treatments pose a risk to plants, animals, and humans, but can be used in ways that greatly reduce this risk, and provide a solution to otherwise hopeless scenarios. 
  • For questions regarding the appropriate chemical to use for a particular situation, or general information on pesticide safety, ingredients, and more, contact the Vermont Agency of Agriculture, Food & Markets’ Pesticide Program.  
  • For questions about certification and continuing education credit opportunities, contact the Vermont Agency of Agriculture, Food & Markets’ Pesticide Program.  
  • For questions about additional training opportunities, contact the UVM Extension Pesticide Safety Education Program.  
  • Special permits are required to apply herbicides in a wetland. Contact Vermont Department of Environmental Conservation’s Wetlands Section for more information.  
  • Herbicides cannot be applied within 200 feet of a Public Water Source Protection Area unless the Water Supply Division is notified. Call 1-800-823-6500 for more information. Similar requirements may be in place for proximity to private water sources.  
  • Forests that are certified organic or adjacent to organically certified agricultural lands may carry restrictions regarding chemical application. Check with the Northeast Organic Farming Agency of Vermont for more information.  
  • The National Pesticide Information Center provides objective, science-based information about pesticides. Check out their website for more information or call 1-800-858-7378. 

text in a table describing chemical treatments for Phragmites

Biocontrol
  • There are currently no known insect biocontrol agents for Phragmites.   
  • Although they will not eradicate Phragmites, livestock biocontrol agents can reduce the severity of impacts from an infestation. More information is needed, and livestock grazing is not an appropriate treatment at all sites. 

 

Citations

Photo Credit

1559066, 1559071,Ohio State Weed Lab, The Ohio State University, Bugwood.org

1237064, Joseph McCauley, US Fish and Wildlife Service, Bugwood.org

Ohio State Weed Lab, The Ohio State University, Bugwood.org

5426607, 5426604, 5426605, Rebekah D. Wallace, University of Georgia, Bugwood.org

5487076, 5487096, Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Information Credit

Center for Invasive Species and Forest Health, Common Reed

GoBotany, Common Reed

Great Lakes Phragmites Collaborative 

Michigan Deparment of Environmental Quality Guide to Phragmites  

US Fish and Wildlife Service Phrag Book