This tall wetland grass is also known as common reed. There are both native and non-native strains of this plant in Washington. Due to its aggressive tendencies and impact to waterways, the non-native strain or haplotype is a Class B designate weed in Washington State.

Because of the limited distribution in the county and the potential serious impact, control of phragmites is required in King County. Phragmites is found in both eastern and western Washington and some infestations are many acres in size. In King County, most infestations are still small and can be eradicated. Because native populations have been found in the region, careful identification by an expert is needed before any eradication measures are taken.

The Washington State Department of Agriculture (WSDA) received a grant from Department of Ecology in 2003 to undertake a statewide phragmites project. The project began mapping all known locations of phragmites using GPS technology and to develop a GIS layer for the State. The researchers submitted samples from each site to Dr. Bernd Blossey at Cornell University for genotyping and input into his national database. All of the populations from King County were identified as the non-native haplotype. For more information on this project and how to distinguish the types of phragmites, check out Cornell University's website.

For more information about phragmites, see the Washington State Noxious Weed Board written findings. If you find phragmites in King County, please notify us through our online infestation form.

To find out where we have records of this weed in King County, use our interactive noxious weed map and search for phragmites or common reed.

Phragmites photos - click thumbnail for larger image