Phragmites marsh Phragmites (in back right of photo) invading a freshwater marsh

Common Reed

(Phragmites)

Phragmites australis

2019 Status in Maine: Widespread. Severely Invasive.

Description: Very tall (to 13') perennial grass growing in dense stands. Leaves: Alternate, entire, yellow-green to greenish-blue, widest in middle, tapering toward pointed tip, very long (~8-15"). Flowers/Seeds: "Fluffy" seed heads start brown-purple, then turn light tan over the fall, persisting through winter. Stem: Round, hollow, with nodes where leaves meet the stem. Dead, tan stalks persist through winter. Rhizome: Dense mat of coarse interconnected roots.

Native range: Europe. How arrived in U.S.: Probably via ship ballast water.

Reproduction: By seed, or by fragments of rhizome dispersed in fill or by water. There are reports of seed banking but length of time is unknown. It can sprout from any rhizome fragment.

Habitat: Open wetlands and wet ditches. Especially damaging in saltmarshes and freshwater marshes. It also frequently grows in roadside ditches and swales.

Similar native species: Native Phragmites americanus can be difficult to distinguish from the invasive P. australis. The native, which is infrequent in Maine, typically grows in small, diffuse stands (not dense) and is comparitively short at ~6'. Also, the middle and upper internodes of P. australis are dull, ridged, and tan during growing season, while P. americanus has smooth, lustrous, red-brown to dark red-brown middle and upper internodes. The native typically grows in fens and tidal marshes, not in disturbed areas.

Invasive and native Phragmites P. australis, invasive, on left; P. americanus, native, on right

Similar non-native species: No other non-native grass is so tall. Escaped Miscanthus ornamental grasses are showy but do not normally occur in wetlands.

Documented Ecological Impacts

Fact Sheets and Identification Links

Control Methods

Small patches (<50' radius) can be cut repeatedly throughout the growing season*, as often as once every two weeks, for multiple years (~5-10 years), depleting root reserves and preventing flowering. This method requires diligence. Larger patches are very difficult to control manually without a persistent, reliable labor source. Herbicides are effective (though follow-up will be needed). The cut-drip method is preferred in small stands (<1 ac) as it is the most precise treatment: bundle and tape 5-10 stems (masking tape works well), cut* live stems late in the growing season, then spray or drip aquatic-formulation glyphosate, with tracer dye, onto cut surface. Foliar application of aquatic-formulated glyphosate can also be effective. If possible, follow up by conducting a controlled burn in the spring following the herbicide application; this can remove old thatch and encourage native plant regeneration. Special rules apply to herbicide use in or near wetlands and water bodies - consult the Maine Board of Pesticides Control.

* Correctly dispose of all plant parts † Follow all label directions when using herbicides

Control Technique Video Demonstrations

Please email invasives.mnap@maine.gov if you have questions about invasive species in Maine

Summer stand of Phragmites Summer stand of Phragmites
Fall stand of Phragmites Fall stand of Phragmites
Phragmites seed heads Phragmites seed heads
Phragmites-new shoots Phragmites-new shoots