Purple Loosestrife (Lythrum salicaria)

A wetland in Minnesota choked by purple loosestrife

Credit: Minnesota Dept. of Natural Resources


Flowering purple loosestrife

Credit: M.J. Kewley - Great Lakes Indian Fish and Wildlife Comission


Purple loosestrife flower spike

Credit: M. Falck - Great Lakes Indian Fish and Wildlife Comission

How did it get here?

  • Arrived in North America as early as the 1800s.
  • Settlers brought it for their gardens, and it may also have come when ships used rocks for ballast.
  • Purple loosestrife has spread across the 48 United States and Canada, with the exclusion of Texas.
  • It is native to Europe and Asia.
Why is purple loosestrife a problem?
  • It is a very hardy perennial and aggressive plant.
  • Purple loosestrife invades wetlands and moist soil areas.
  • It crowds out native plants.
  • It has very little food value for animals.
What does it look like?
  • Purple loosestrife can be 4-7 feet tall and have up to 30 flowered spikes.
  • Each plant can produce 2.5 million seeds a year.
How do we control purple loosestrife?
  • Small patches can be dug up by hand and then dried and burned.
  • Herbicides can be used, but they will affect other plants and possibly kill some of the good plants.
  • Galerucella beetles feed only on purple loosestrife, these beetles can be released on the plants, but this can take a long time to bring an infestation under control.






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