During July, I notice gardens, roadside ditches and wetlands with the invasive, non-native Purple Loosestrife (Lythrum salicaria). This non-native plant destroys our wetlands by choking out native species and in turn wildlife habitat. It also costs millions of dollars to eradicate from our natural areas once it spreads. 


 I understand the attraction because it has pretty bright purple-magenta and is a long blooming plant.  Sure, it attracts a few pollinators too. But is is so harmful and aggressive in our wetlands, and doesn’t support as many wildlife as well as our native wetland plants.  If you cannot guarantee your plant won’t spread by seed or won’t cross pollinate with other loosestrife (both native and non-native), PLEASE dig and destroy it before it goes to seed!  Each invasive loosestrife plant can produce a million or more seeds per year.

There is a native Winged Loosestrife (Lythrum alatum) similar in color ( more purple violet than purplish magenta), shorter in height, with smaller flowers and leaves, preferring moist areas. Do not confuse the two.

native Wiinged Loosestrife

Native Winged Loosestrife is only 1-2 feet tall, likes moist soil, sun, smaller flowers

Currently there has been some success using a beetle to feed and eradicate some stands of this invasive loosestrife.   But if you can help eliminate or slow the spread of this pretty, ugly plant, even better. Here are a few suggestions:

  • Please don’t use it in your garden or accidentally spread the seeds when walking or boating through a natural area. In fact, it is illegal to sell or distribute this plant.
  • Keep an eye out for Volunteer opportunities to help eradicate this plant from natural or public areas
  • If you see it growing  in a public area or natural area, report it to the park district,  forest preserve, city, county or whoever owns the land since it’s easiest to eradicate when there’s only a small patch growing.
  • It is illegal to sell,  distribute, or cultivate this plant  in Illinois.  If you discover anyone doing this, assume they may not know about this noxious weed and start educating them using the websites listed below.  If they do not stop,  contact your County’s or City’s wetland/storm management department, your local Illinois dept. of Natural Resources, or Chicago Wilderness.
  • Use beautiful native plants instead because of all their benefits.  Some recommendations include the Winged Loosestrife (Lythrum alatum), Blue Flag Iris (Iris virginica shrevei ), Marsh Marigold (Caltha palustris),  Marsh Blazing Star (Liatris spicata), Showy Tick Trefoil (Desmodium canadense) for moist areas.  There are many more.
  • Educate others about this and other invasive species.

For information and suggestions, please see the following websites:

Illinois Purple Loosestrife Info

Wisconsin Purple Loosestrife Info.

Manitoba Purple Loosestrife Project FAQ

Here is a website with a educational PDF you can print and share with others:  PCA Alien Plant Working Group

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