Common Reed (Phragmites)
What is it?
Common reed, also known as phragmites, is a large perennial, grass or reed with creeping rhizomes. It typically is found in or near wetlands but also can be found in sites that hold water, such as roadside ditches and depressions. Phragmites form dense stands, which include both live stems and standing dead stems from previous years. The plant spreads horizontally by sending out rhizome runners, which can grow 10 or more feet in a single growing season, rapidly crowding out native grasses.
Is it here yet?
Yes. Extensive stands exist in both eastern and western Washington in marshes and along river edges and shores of lakes and ponds.
Why should I care?
The Washington State Noxious Weed Control Board has listed common reed as a Class B noxious weed. The goals are to contain the plants where they already are widespread and prevent their spread into new areas. Cutting has been used successfully for control. Because it is a grass, cutting several times during a season, at the wrong times, may increase stand density. However, if cut just before the end of July, most of the food reserves produced that season are removed with the aerial portion of the plant, reducing the plant's vigor.
What should I do if I find one?
How can we stop it?
Do not purchase, plant, or trade this species.
What are its characteristics?
- Common reed is a perennial wetland grass that is able to grow to heights of 15 feet or more.
- Leaves are 8-16 inches long, .2 to 1.5 inches wide.
- Leaf blade is smooth and lanceolate, which tapers from a rounded base toward its top; lance-shaped.
- Their hollow stems can reach 12 feet tall and have a rough texture.
- The flowers are dense, silky, floral spikelets and grow from 1–16 inches long. These feathery plumes are purplish in color and flower in late July and August.
How do I distinguish it from native species?
Non-native common reed may be confused with native populations of phragmites. Native genotypes are less dense and the stems are thin and shiny. Native phragmite flowers are also less dense.
Where can I get more information?
- Washington State Noxious Weed Control Board
- U.S. Department of Agriculture
- University of Florida's Center for Aquatic and Invasive Plants
- Michigan Department of Natural Resources and Environment