Why Are Phragmites australis a Problem?  Why Should I Care?


  • Are invasive plants causing damage to Ontario’s biodiversity, wetlands and beaches.
  • Crowd out all other vegetation.  They are so tall that they shade out other plants and when they die Phrag continue to stand, creating the “standing dead”.
  • Shade and cool the soil, creating a microclimate that affects what grows and survives.
  • Root systems can reach nearly two metres (six feet) below ground and release toxins that keep other plants from growing.
  • Provide poor or loss of habitat and food supplies for wildlife, including several Species at Risk.
  • Stalks are rigid and tough, and do not allow for wildlife to easily navigate through or nest in a stand.  Stalks can trap and kill turtles and animals as large as deer.
  • Can cause lower water levels as water is transpired faster than it would be with native vegetation.
  • Grow very quickly  i.e. In Long Point, Phragmites have spread from only 17 hectares in 1995 to now covering thousands of hectares.
  • Increase fire hazards as stands are composed of a high percentage of dead stalks that are very combustible.
  • Affects on agriculture and crops can lead to economic losses.
  • Cause road safety hazards by blocking views at intersections and at the end of driveways.
  • Impact recreational activities such as swimming, boating and angling.
  • Affect our water-based tourism and the local economy.
  • Destroy our beaches, making it impossible to access the water.
  • Once established in water there are no approved eradication treatments in Canada.
  • Monoculture stands negatively affect property values and raise aesthetic concerns.
  • Costs to control and eliminate escalate every day no action is taken.


University of Waterloo Magazine
Ontario Ministry of Natural Resources, Invasive Phragmites-Best Management Practices, Ontario
Ministry of Natural Resources, Peterborough, Ontario. Version 2011.15p