Purple Loosestrife Controls



"Purple Loosestrife: What You Should Know, What You Should Do" (brochure).  This brochure can be found online at: www.purpleloosestrife.org/infosite.  

THE COMPANION BROCHURE was written in Canada, but is very useful in Wisconsin. Please take a moment to read this additional information specific to our state.

WISCONSIN LAW bans the sale, distribution, planting, or cultivation of Purple Loosestrife (PL). The ban covers both Lythrum salicaria and L. virgatum and includes ALL cultivars, hybrids, and so-called sterile varieties. Report cultivation violations to local law enforcement officials. (If they have no local weed policy, work with local government to establish one that can support enforcement.) There is a $100 fine per violation. Sales of the plant should be reported to WDATCP at 608-224-4571.

HOME GARDENS WITH PL ARE A BIG PROBLEM. Seeds wash into nearby waters and wetlands with many home gardeners apparently unaware that this is a problem. Help us spread the word to eliminate PL in gardens! Some similar native Wisconsin plants that can replace it in moist gardens include ironweed, bergamot, joe-pye weed, marsh milkweed, great lobelia, wild blue phlox, and beardtongue.

HELP US UPDATE OUR WISCONSIN PL DISTRIBUTION MAP by reporting PL locations (latitude and longitude points from a GPS are best) with area, size, and land owner’s name and phone number to 'PL Bio-Control' at WDNR Research Center (address listed at bottom). www.glifwc-maps.org

THE MOST EFFECTIVE IMMEDIATE CONTROL of PL is selective use of herbicides (treat only PL foliage or cut stems). However, this method usually requires follow-up spraying, is expensive on large sites and can disturb wetlands. Non-specific glyphosates kill all plants they touch, so avoid broadcast spraying. Use other mechanical controls, such as pulling or digging if plants are young and small. These fast, traditional methods must be used on populations of PL that can quickly spread seeds around new areas.

BIOCONTROL (BC) IS LIKELY THE BEST LONG TERM CONTROL since it is natural, inexpensive, and permanent. Wisconsin DNR started BC for PL in 1994 and the process is very promising. WDNR and its cooperators have released insects on over 300 sites statewide, though still less than ¼ of 1% of all infested Wisconsin sites. Monitoring shows the insects survive exclusively on PL, are very hardy, and can cut PL seed production and growth on small sites within just a few years. Large infestations of PL will take longer. The insects are not usually fatal to PL, but cut seed production and plant vigor, making it less competitive with and slowly replacable by native plants. Biological Control of Purple Loosestrife (word .doc)

THE KEY TO EFFECTIVE, LONG-TERM PL CONTROL seems to be an integration of traditional controls and BC: Prevent human use and dispersal of PL. Remove pioneer plants quickly by digging, pulling or chemicals (small areas). Selectively treat with herbicides any size area for which you have adequate resources. Start BC to prevent seed production on larger areas and begin removing large amounts of plant material or even reducing numbers of plants. BC might eventually replace most traditional methods if control insects become ubiquitous. Be sure BC is started in your area!

THE CONTROL CHART IN THE BROCHURE is based on infestation size and PL density and can help you choose the best control for your site. It is a suggestion only, so plan wisely based on your unique site needs and resources. Use traditional methods where they will be effective and BC everywhere else! Save some small isolated infestations for beetle insectaries. WDNR's bio-control budget is small; many citizens must help by rearing and releasing control insects into their local wetlands. Consider joining in!


What You Should Know About Purple Loosestrife (slide show)
- slide show overview of purple loosestrife. Includes information on biological control. Summer 1999. Available through GLIFWC (email)




This page has been established to raise awareness of several invasive non-native plants and their ecological impacts in the upper Great Lakes region. We hope to provide effective tools for your educational, management, and research needs.




These Wisconsin DNR Personnel are regional Aquatic Plant Management Coordinators (APM-C)

Northern Region


Eastern Half


Laura Herman


107 Sutliffe Ave.

Rhinelander, WI 54501


Western Half


Frank Koshear


1401 Tower Ave.

 Superior, WI 54880



North East Region


Mary Gansberg (and others)


PO Box 10448

Green Bay, WI 54307-0448


West Central Region

Debra Konkel


1300 W. Clairemont Ave.

Eau Claire, WI 54702-4001


South East Region

Craig Helker


4041 N. Richards Street

Milwaukee, WI 53212

South Central Region

Susan Graham


3911Fish Hatchery Rd.

Madison, WI 53711






Counties: Florence, Forest, Iron, Langlade,Lincoln, Oneida, Price,

Taylor, Vilas






Counties: Ashland, Barron, Bayfield, Burnett, Douglas, Polk, Rusk, Sawyer, and Washburn,






Counties: Marinette, Oconto, Menominee, Shawano, Waupaca, Door, Kewaunee, Brown, Outagamie, Waushara, Winnebago, Calumet, Manitowoc, Marquette, Green Lake, Fond du Lac





Counties: St. Croix, Dunn, Chippewa, Clark, Marathon, Portage, Wood, Adams, Juneau, Pierce, Pepin, Buffalo, Eau Claire, Trempeleau, Jackson,Monroe, La Crosse, and Vernon






Counties: Sheboygan, Washington, Ozaukee, Racine, Kenosha, Waukesha, Milwaukee, Walworth






Counties: Crawford, Richland, Sauk, Colombia,  Dodge, Jefferson, Dane, Iowa, Grant, Green, Rock, Lafayette

Statewide Biological Control Program Information

Brock Woods



WDNR Research Center

1350 Femrite Dr.

Monona, WI 53716 1/14/02


Membership meeting information

Board meetings are the third Tuesday of the month at 7:00pm.

Membership meetings are the fourth Tuesday at 7:30pm. With Guest Speaker To discuss farm issues and conservation efforts.

All Meetings are held at the VFW Hall, 133 E. Lakeside St.(off John Nolen drive). in Madison.