Since 2008, we have reported on the dangers of pyralid herbicides (including Milestone, Forefront and other trade names) which turn grass clippings, manure, or hay into killer compost or mulch that can ruin gardens and farmland for years. Despite ample evidence that these deadly herbicides are damaging fields and gardens, and despite our calls for the companies and the Environmental Protection Agency (EPA) to solve this problem, we were angered to learn that another deadly pyralid herbicide, Imprelis (aminocyclopyrachlor), was widely sold in the spring of 2011, following its approval by the EPA in August 2010.
Invented by a team of scientists at DuPont, aminocyclopyrachlor is marketed to control weeds in cool-season lawn grasses, especially bluegrass (it is not generally sold in warmer climates, where bluegrass lawns are rare).
DuPont never denied that Imprelis-treated lawns would create killer compost. Lost in a 19-item bulleted list on Page 7 of the 9-page Imprelis label, we found this language:
“Do not use grass clippings from treated areas for mulching or compost, or allow for collection to composting facilities. Grass clippings must either be left on the treated area, or, if allowed by local yard waste regulations, disposed of in the trash. Applicators must give verbal or written notice to property owner/property managers/residents to not use grass clippings from treated turf for mulch or compost.”