Apply Experimental Treatments

A key objective of our adaptive management approach is to establish a coordinated experimental treatments of Phragmites.  We will control be enlisting several partners to strategically apply alternative treatment methods throughout northeast Wisconsin.  

Experimental treatments will follow the scientific method, with the end goal to identify the most effective type and application time of herbicide treatment.


Imazapyr and Glyphosate

To give some background, phragmites management proceeds most commonly with a herbicide application. Often, mowing and/or burning are secondary treatments used in combination with herbicide application. The two herbicides known for controlling Phragmites populations are the chemicals imazapyr and glyphosate. Glyphosate is the active ingredient in Monsanto's Roundup. Imazapyr is more effective at killing Phragmites, but there are more serious ecological effects. This is of great importance, since Phragmites grows in senstitive wetlands and, in our case, areas of concern. There is no consensus in the scientific community about which herbicides are most effective for minimizing Phragmites growth or spread with the least negative site impact. So, this present an opportunity to study the effects of imazapyr vs. glyphosate or a glyphosate-imazapyr mixture.

What we will learn from this Experiment

  • How many (or what frequencies of) appliations of glyphosate are necessary to adequately control local Phragmites populations?
  • What is the longevityof native seedbanks at Phragmites sites?
  • What is the expected diversity of native plant communities after repeated Phragmites treatments?
  • How successful are mechanical treatment methods compared with chemical treatment methods?


June treatment of imazapyr at 2% or 5% formulation is more effective than June treatment of 2% or 5% glyphosate or glyphosate + imazapyr.


In late June/early July or September, Phragmites patches will be foliar sprayed with either glyphosate, glyphosate and imazapyr solution, or pure imazapyr and a surfactant. The research design will include additional, site specific variations, but the focus will be on the herbicides used for the experiment. We will also use the protocol.

Independent Variables

  • herbicide type
  • herbicide concentration
  • timing of application
  • community type
  • soil type
  • mowing time in correlationg with herbicide timing and treatment, if any
  • method of herbicide application (wicking, backpack sprayer, ATV, etc)

Response Variables

  • Percent cover of Phragmites, native vegetation, species richness, and other non-natives
  • stems per square meter (quadrant)