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Reed Canarygrass

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Phalaris arundinacea
Grass Family

Identification Tips

  • Reed canarygrass is a perennial grass with stems that can grow to 6 feet tall.
  • Ligules are very long.
  • In late summer reed canarygrass forms a seed head that is gold, red, or purplish.
  • Reed canarygrass has an extensive system of roots and rhizomes that can extend 18 inches below the soil surface.


  • In Washington and Oregon, reed canarygrass is a serious threat to wetland ecosystems.
  • Because of its capacity to form dense monocultures, reed canarygrass reduces habitat complexity and decreases the availability of food for many wildlife species.

Habitat & Distribution

  • Reed canarygrass grows best in moist sites such as wetlands and riverbanks.
  • It can also be found in poorly-drained soils near canals and streams.

Reproduction & Spread

  • Reed canarygrass reproduces by seed and roots.
  • Creeping rhizomes can force out native species and form a dense monoculture.


Integrated Pest Management

  • Integrated Pest Management (IPM) involves selecting from a range of possible control methods to match the management requirements of each specific site. The goal is to maximize effective control and to minimize negative environmental, economic, and recreational impacts.
  • Use a multifaceted and adaptive approach. Select control methods reflecting the available time, funding, and labor of the participants, the land use goals, and the values of the community and landowners.  Management will require dedication for a number of years and should allow flexibility in methods.

Planning Considerations

  • Survey the area for weeds, set priorities, and select the best control method(s) for the site.
  • Select control practices to minimize soil disturbance. Minimizing disturbance prevents secondary infestations of weeds.
  • Begin work on the perimeter of the infestation and move inward.
  • Monitor the site and treat plants that germinate from the seed bank.
  • Revegetate the treatment areas to improve ecosystem function and prevent new infestations.

Early Detection and Prevention

  • Minimize soil disturbance from vehicles, machinery, and over-grazing.
  • Reed canarygrass is easiest to identify in summer when the seed heads have formed.
  • Most infestations will require mechanical or chemical control.
  • Monitor and re-treat infestations as necessary. Ensure any existing plants do not produce and release seed.
  • Thoroughly clean tools, boots, and vehicles after working in or traveling through an infested area to prevent the spread of noxious weeds.

Manual, Mechanical, & Cultural Control

  • Combine mowing or tilling with a proper flooding regime to control reed canarygrass (minimum 18 inches water depth for at least 4 weeks through the spring).
  • Solarization can eliminate small infestations of reed canarygrass. Use black or clear plastic to heat the soil and kill weed seeds. Leave the plastic in place for at least 1 year to effectively solarize infestations.
  • Plant fast-growing shrubs and trees to shade out reed canarygrass infestations. Reed canarygrass cover can be reduced to as little as 20 percent in shade.
  • Keep your tools, vehicles, and clothing free from weed seeds to prevent spread.

Herbicide Control

  • Apply herbicides at proper rates and for the site conditions or land use specified on the label. Follow all label directions and wear recommended personal protective equipment (PPE).
  • In established stands, mow canarygrass and spray the regrowth when it is the height recommended on the label.
  • Monitor areas for missed and newly germinated plants.

Specific Herbicide Information

Herbicides are described here by the active ingredient.  Many commercial formulations are available containing specific active ingredients but often are not formulated for use near aquatic sites. Always be sure to select an aquatically-approved herbicide and surfactant for use near water.  References to product names are for example only.  Directions for use may vary between brands.

  • Since reed canarygrass frequently grows in wet areas, only aquatic-approved herbicides are allowed in many situations. As with all herbicide use, be sure to read and follow all label instructions and to abide by all state regulations.  Permits may be required to make herbicide applications in a wetland.
  • Glyphosate (e.g. Rodeo) with a surfactant approved for use near water works well to kill reed canarygrass; applications without surfactant may also be effective. Glyphosate is a non-selective herbicide that is effective on grasses, but can kill or injure most other plant species, as well.
  • Follow-up monitoring and treatment is necessary for several years to ensure complete kill.

This BMP does not constitute a formal recommendation. When using herbicides, always consult the label


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