Reed Canarygrass
Phalaris arundinacea

This Class C weed is widespread in Washington State and control in King County is not required, but strongly recommended where possible, especially in restoration projects where wetland functions are being restored.

Reed canarygrass is a tall wetland grass that forms dense, single-species stands. It chokes out streams and ditches increasing flooding and impeding salmon and other fish. Although used at times for forage in wet pastures, it can cause indigestion and illness in livestock.

Reed canarygrass grows 3 to 6 feet tall and has sturdy hollow stems up to ½ inch wide, with reddish coloring near the top. The leaf blades are flat, hairless, wide, and come off the stem at a 45 degree angle. Flower spikes are large and compact on stems high above the leaves in June and July.

This aggressive grass poses many challenges to management and creates significant problems for restoration projects. It spreads by rhizomes, fragments and seeds. The dense rhizomatous mats exclude other roots and make removal highly difficult. Stems fall and form mounds by the end of summer, further inhibiting native wetland species from re-colonizing infested areas.

For more information about reed canarygrass, please follow this link to the Department of Ecology.