Dead white pine trees. White pines are one species that's under assault by the DuPont weedkiller, Imprelis. bobistraveling  Flickr/CC / treehugger.com

By Brian Merchant
11 July 2011 Brooklyn, New York – Unruly herbicides are making headlines again: A couple weeks ago, it was the fact that the world’s top-selling weedkiller was causing birth defects. This time, it looks like the brand new herbicide Imprelis, manufactured by the chemical giant DuPont and okayed for use by the EPA, is causing mass tree deaths in a number of vulnerable species across the US. UPI reports:

Landscapers switched to Imprelis this year to control weeds because it was claimed to be safer for the environment than predecessors … Amy Frankmann, head of the Michigan Nursery and Landscape Association, said she has not seen such widespread tree death since the emerald ash borer ravaged ash trees. “I’d say this is right up there as far as the significance and losses,” Frankmann said. “The customers are calling: ‘My trees are dying, what’s up?’ ” said Mark Underwood, a Michigan lawn care specialist. “We’ve never experienced anything like this.”

The herbicide is suspected of killing Norway spruce and white pine trees en mass all over the country. According to UPI, even DuPont seems to be fessing up — the company is advising that the weedkiller not be sprayed near the trees. I only hope that DuPont has some grasp of the irony here: It’s come up with, as far as I know, the only “environmentally friendly” herbicide that literally causes mass tree deaths.

New Weedkiller May be Causing Mass Tree Deaths in U.S.