Southeastern Wisconsin Invasive Species Consortium, Inc.


Roadside Inventory and Management

A team of committed representatives is currently meeting with southeastern Wisconsin roadside maintenance crews to deliver location and population size data for five invasive species which were mapped in 2011, 2012 and 2013 through the efforts of more than 150 SEWISC volunteers.   Wild parsnip (Pastinaca sativa) was mapped by citizen scientists in 2012 while common and cut-leaved teasel (Dipsacus sylvestris and D. laciniatus), common reed grass (Phragmites australis) and Japanese knotweed (Polygonum cuspidatum) populations were the target of 2011 efforts. 

With the aid of Great Lakes Restoration Initiative funding through the Environmental Protection Agency, the Ozaukee Washington Land Trust (OWLT) has partnered with SEWISC to schedule meetings with key representatives in more than 100 cities, towns and villages in Washington, Sheboygan, Ozaukee, Milwaukee, Racine and Kenosha Counties.  

 Roadside 1Roadside 2Roadside Mower

Nearly 5,000 poulations of target invasive plant species were mapped by our volunteers.

2013 SEWISC Survey Layout no pictures

How You Can Help Stop the Spread of Invasives on Roadways

Develop a program by following the guidelines in the SEWISC ROW Invasive Species Management Plan.  The basic elements of a program to contain and control invasive plants on right-of-ways are simple to prioritize and outline:

  • Adjust and customize ROW mowing to prevent spreading seed, and when possible, to prevent seed set in established patches.  In other words, don’t spread the species by mowing.  In general this means a full-mowing of the ROW in the month of July.
  • Keep a close eye on all your roadways and identify newly-occurring individual plants and very small new patches of these invasives.
  • Eliminate/eradicate those newly-occurring individual plants and very small new patches using methods appropriate for the species.
  • and, Sustain this program on a continuing basis. 

Unless resources are available to accomplish all of these priority control tasks, aggressive and more costly control of well-established populations should only be conducted if it can be justified for specific localities (e.g. a roadside population poses a definite threat to an adjacent high-quality natural area).  DO NOT spread established populations!

For help with:

  •        Monitoring roadways for new colonists,
  •        Identification of plants,
  •        Consultation on seed maturity status of plants,
  •        Specific control recommendations, or
  •        Anything else you need to help you with invasive plant control,

Contact us at:

What SEWISC could really use from you:

Help with formulating a reasonable cost estimate for this work!



Indicates Pop-up Image zoom-img