First applied in the fall of 2010 and followed by widespread reports of damage to landscape plants (primarily evergreens, but also various deciduous trees and shrubs) beginning the following spring and continuing thereafter, many of us are aware of the controversy surrounding the herbicide Imprelis® labeled for use on residential, commercial, and recreational turf and sod farms. Based on thousands of reports of damage, further use of the herbicide was prohibited about a year after being approved for use as a post emergent herbicide for the control of broadleaf weeds in turf (August 2010) and DuPont, the herbicide’s manufacturer, initiated a voluntary claims resolution process for trees that may have been damaged by the ill-fated Imprelis. Although the initial, and subsequently extended, deadlines for initial claims (November 30, 2011) and the submission of supporting documentation (February 1, 2012) have passed, lawsuits are now being filed against DuPont.
Regardless of the outcome of the legal process, questions remain about the care of damaged trees that are still living and the handling of dead trees. As cautioned on the Imprelis label, grass clippings from treated areas should not be used for mulching or composted. Remember, too, that Imprelis is easily transported to distant areas and surface waters in runoff and leaches within the soil. Subsequent warnings have been issued related to the use of woodchips from damaged trees and shrubs. Based on the rate of degradation of the herbicide in the environment, these restrictions should be followed until at least the end of the 2012 growing season and until further research results are available. It is also recommended that susceptible species not be planted in treated areas until the fall of 2012.
For additional information on the Imprelis situation see the following articles or call the DuPont Imprelis® Hotline at 866-796-4783.
U.S. Environmental Protection Agency (EPA) order directing DuPont to immediately halt the sale, use or distribution of Imprelis herbicide (August 11, 2011)
29 Lawsuits Filed Against DuPont over Tree Damage – Waukesha County Homeowners Allege Herbicide Kills Conifers. JSOnline; Milwakee Journal Sentinal (February 23, 2012).
What’s New With Imprelis? – Questions Remain About Residual Soil Activity and Recovery of Trees Affected by New Herbicide. Michigan State University Extension News (February 3, 2012).
The Facts About Imprelis® – Updated FAQ About the Claims Resolution Process. DuPont (January 17, 2012).
The Facts About Imprelis®. DuPont.
Fall 2011 Guidelines for Planting Trees on Properties That Have Been Treated With Imprelis® Herbicide (Dupont).
Imprelis Herbicide Injury: 2011 PPDL Host List. Purdue University Extension (January 16, 2012).
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