Giant Reed Grass
(Phragmites australis)

Giant reed grass in summer

Giant reed grass rhizomes ------------------------------------------------------ Giant reed grass in winter

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• Characteristics
• Methods of control
• Links to external sites
• 

Characteristics:

1. U.W. Green Bay Herbarium:
   Phragmites australis is a widespread and aggressive invasive species.  It appears to be nearly global in distribution in freshwater wetlands, it is found throughout the continental U.S.A. and is widely distributed in Wisconsin, although it appears to be most common in the southern part of the state, along the Great Lakes and in and around cities.  It quickly colonizes  roadside ditches and  heavily disturbed sites and more slowly invades our native, sunny wetlands of moist soil to shallow water.  In a few locations it has also become well established in deeper water sites.  It appears to be steadily increasing in Wisconsin and during the recent low water levels in  Lake Michigan (1999-2007) it has dramatically expanded into the  newly exposed lakebed, forming large clones which exclude virtually all other plants.
2. MI Dept. of Environmental Quality:
   The invasive, non-native variety of Phragmites australis, commonly known as phragmites, is a perennial wetland grass that can grow up to 15 feet tall. Phragmites tend to grow creating dense stands which degrade wetlands and coastal areas by crowding out native plants and animals, blocking shoreline views, reducing access for swimming, fishing, and hunting, and potentially creating fire hazards from dry plant material. Phragmites can generally be found growing in coastal and interior wetlands, lake margins, roadside ditches, and other low, wet areas, although it can also be found in dry areas.
3. WI Lakes Partnership, Lake Tides:
   Phragmites is a perennial grass that thrives in moist soils. Its reeds, or canes, are unbranched, rigid and hollow and can reach heights over 12 feet. A large, feathery seed head is produced in late July through September. Like all grasses, phragmites dies back to the ground in late fall. The canes are tough enough to remain standing for a few years after they die.

   Phragmites spreads primarily by vegetative reproduction. Thick, intertwined roots can reach six feet deep while rhizomes (horizontal roots) spread the plant laterally. The plant also sends out stolons, or runners, with nodes every foot or so that are each capable of growing a new plant. Stolons from aggressive strains of phragmites can easily exceed fifty feet in a single growing season.

   Native to many places in the world, phragmites has been and continues to be harvested by numerous cultures for a variety of purposes. For example, its long, strong canes make excellent roof thatch material. Native phragmites exists in Wisconsin and grows in sparse stands interspersed harmoniously with a variety of other native plants. It does not usually reach more than 8 feet tall. Its invasive cousin originated in Eurasia and poses a double threat here in North America. It not only out-competes native phragmites, it also interbreeds with the native strain, thus strengthening the aggressive tendencies of future plants.

   Because phragmites can be so aggressive, the Wisconsin Department of Natural Resources (DNR) recommends landowners watch for new stands of phragmites and control it before it has a chance to expand.

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Methods of control:

• WDNR PDF document

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Links to other sites

• Wisconsin Wetlands Association
• UWGB Herbarium
• MI Dept. Environmental Quality
• WI DNR Photo Gallery
  
  

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