Reed canary grass

Phalaris arundinacea

Invader Images

    • Seed head of Reed Canary grass
      Seed head of Reed Canary grass
    • The ligule is transparent (where blade and sheath come together)
      The ligule is transparent (where blade and sheath come together)
    • Reddish rhizomes near the soil surface
      Reddish rhizomes near the soil surface
    • Flowering head of Reed Canary grass
      Flowering head of Reed Canary grass

Common Look-alikes

    • Native bluejoint grass (Calamagrostis canadensis) also has a transparent-white ligule, but is less coarse textured than RCG, has smaller seed with fine hairs used for wind dispersal, can have dark colored joints, and the rhizomes near the soil surface are not reddish colored.
      Native bluejoint grass (Calamagrostis canadensis) also has a transparent-white ligule, but is less coarse textured than RCG, has smaller seed with fine hairs used for wind dispersal, can have dark colored joints, and the rhizomes near the soil surface are not reddish colored.

Identification

Appearance

Phalaris arundinacea is a cool-season perennial grass that grows to 6 ft. (1.7 m) tall. Reed canarygrass is variable in morphology, so characteristics may depend upon the habitat.

Foliage

Leaf blades are flat, 1-4 ft. (0.3-1.2 m) long, up to 0.75 in. (1.9 cm) wide, glabrous and taper gradually. The ligule is membranous (transparent) and long.

Flowers

The spreading flower/seed heads arise from hairless stems and can be green, purple, or brown in color and usually 3-6 in. (7.6-15.2 cm) in length. Flowering occurs from May to July.

Fruit

The inflorescence color changes from green to purplish to tan as the seeds mature. There are both sterile and fertile lemmas.

 

Biology

ECOLOGICAL THREAT

Reed canary grass forms large, monotypic stands that harbor few other plant species and are little use to most native wildlife. It constricts waterways by promoting silt deposition, yet may also encourage erosion of soil beneath its dense mats in places where water flows rapidly. Overtime, it builds up a tremendous seed bank that will erupt when sites are treated for this invasive.

ORIGIN

Both Eurasian and native ecotypes [genetically distinct populations] of reed canary grass are thought to exist in the United States. Invasive populations may be descendants of non-native cultivars or ecotypes, although this is not clear. Aggressive strains have been planted throughout the United States since the 1800s for forage and erosion control. Reed canary grass has become invasive or problematic in New England and across North America.

HABITAT

Wetland margins, meadows, fields, riverbanks, shoreland, disturbed areas

LIFE CYCLE

Reed canary grass is large and coarse, reaching up to nine feet in height. Its flat, bluegreen leaves are roughly textured. In June and July, large flower plumes are produced, which are green with a purplish tinge, eventually becoming light tan in color. The stems do not remain standing though the winter.

Management Options

This is considered a watch list species

MECHANICAL CONTROL

Physical Small patches may be effectively dug up or hand pulled. They may also be covered by black plastic for at least one growing season. Be watchful of rhizomes spreading beyond the edge of the plastic. Mowing twice yearly (early to mid-June and early October) can help control dense stands. Disrupting the roots every two to three weeks weakens established plants and depletes the seed bank.

CHEMICAL CONTROL

Chemical In small populations, glyphosate can be applied directly to cut stems to avoid collateral damage to native plants nearby. Herbicide is best applied in early spring when most native species are dormant. Before applying herbicide, remove dead leaves from the previous year to maximize growing shoot exposure. Use a formulation of glyphosate designed for wetlands.

 

**Be careful not to damage or kill nearby native plants when conducting management work. And when using herbicides, always follow the instructions on the label.**