The Wilmer Wetland project was initially begun in 1991 with the breaking of a tile line that drained a one-acre, reed canary grass (RCG)-infested depression in the larger Wilmer Meadows.  After a few years it was apparent that there was not deep enough water, over a long enough time period, for this invasive plant to diminish enough for native wetland species to become established. Relying on recent Midwest research addressing the control of reed canary grass, work commenced in spring 2010.  With USFWS funding support, the purpose is to use the site preparation techniques of periodic herbicide treatment and tilling (see Reith Village Bio-retention Basin project) to provide long-term control of reed canary grass in these small, isolated seasonal wet depressions.  It is envisioned that, once the vegetative reproduction potential of RCG appears to be exhausted, sedge meadow species will be introduced, and the hydrology reestablished and controlled, such that RGC will maintain itself as a minor component in an otherwise diverse herbaceous wetland community.

In May 2010 the wetland basin was broadcast sprayed with herbicide. In addition, a surrounding upland perimeter that had RCG was treated and will be restored as a buffer of native herbaceous species.  Tilling commenced on the treated area that summer.  As expected, RCG reestablished itself the following year in response to the tilling breaking up the rhizome mass and stimulating the dormant buds (which not affected by the herbicide) to sprout new growth.  This once-a-season herbicide application and tilling was done in 2011 and 2012.

Wilmer site RCG infestation- pretreatment (May 2010)

Results of first herbicide treatment (August 2010)

Site first tilled (August 2010)

Existing site high-water hydrology (April 2011)

RCG re-infestation – 1st growing season after initial herbicide/tilling treatment (June 2011)

Installation of new drainage tile connected to water control box (July 2012)

Installation of water control box at appropriate elevation grade (July 2012)

In the summer of 2012 a water control structure was installed.  This will enable us to maintain a dry site in the spring and fall so that further herbicide application or tillage can be feasible within a longer timeframe.  It will also provide the opportunity to have a dry enough seedbed in late fall to permit seeding.  Once seeding has occurred the hydrology will be restored to that of more normal seasonal fluctuations.  But there will be the ability to control water levels such that native plants better thrive and any remnant RCG will be stressed.   The need for continued herbicide/tilling site preparation will be evaluated in 2013, with the expectation that a sedge meadow community will be established by 2017.