Common reed
(Phragmites australis)

Description:
It can grow up to 6 meters high in dense stands and is long-lived. Phragmites is capable of reproduction by seeds, but primarily does so asexually by means of rhizomes. Recent research has now shown that native and introduced genotypes of this species currently exist in North America.

The species is invasive particularly in the eastern states along the Atlantic Coast and increasingly across much of the Midwest and in parts of the Pacific Northwest.

Phragmites australis is a clonal grass species with woody hollow culms which can grow up to six meters in height. Leaves are lanceolate, often 20-40 cm long and 1-4 cm wide. Flowers develop by mid summer and are arranged in tawny spikelets with many tufts of silky hair. P. australis is wind-pollinated but self-incompatible. Seed set is highly variable and occurs through fall and winter and may be important in colonization of new areas. Germination occurs in spring on exposed moist soils. Vegetative spread by below-ground rhizomes can result in dense clones with up to 200 stems/m2.

• Mechanical: Mowing, disking, dredging, flooding, draining, burning, and grazing.
• Biological: No biological controls agents for fennel are known.
• Herbicide: Successful approach on National Wildlife Refuges appears to be the application of glyphosate late in the growing season, followed by prescribed burning or mechanical removal of dead stalks. One reason for the reliance on chemical control is that habitat management such as cutting, mowing and disking actually encourages the spread of Phragmites.

For More Information:
Detailed information about common reed is available at the Washington State Noxious Weed Control Board Web Site.