Phragmites invade Grant County water

This is the last article from the Grant County Weed Board for this year. The information provided has helped Grant County residents with weed control, as represented by feedback reaching this desk. Thanks so much for supplying information-rich articles for the readers.

Phragmites, or common reed, is a large perennial, wetland grass that can grow to heights of 15 feet or more. It is an aquatic invader in Grant County and is also present in over half of the counties in Washington.

Phragmites is native to Europe and was introduced to North America in the early 20th century, by way of packing materials and ballast frequently dumped into coastal marshes by trade ships.

This weed typically grows in wetlands, along lake edges and roadside ditches, and in other low, wet areas. It spreads rapidly by rhizomes, which are horizontal underground stems that put out lateral shoots. These rhizomes can reach up to 60 feet in length and grow more than six feet per year.

Rhizomes, when broken by human activities like disking or digging, can quickly take root in new locations and produce new plants.

As noted, mature phragmites plants can reach heights of 15 feet or more, yet 80 percent of the plant is underground in a dense root ball that grows to a depth of six feet or more. Leaves grow up to 24 inches long by two inches wide. Flowerheads are gray to tan in color and drape to one side in a plume-like fashion.

Each mature phragmites plant can produce as many as 2,000 seeds, which are viable for one to two years. New stands of phragmites can develop from seed, but this process is much slower than the spread of new plants by rhizome fragments.

Controlling the spread of phragmites is critical to the restoration of native wetland plant communities and protection of fish and wildlife habitat. Now is the time to identify and control invasive plants, whether it be phragmites or other noxious weeds. If you need help identifying a particular weed or need control information, please feel free to call our office at (509) 754-2011, Ext. 4710, or visit our website at www.grantcountyweedboard.org.