Last month there were a number of stories on the mass deaths of Norway spruce and white pine across the U.S., with all signs pointing towards DuPont’s herbicide “Imprelis” as the culprit.

The evidence is in, and indeed Imprelis appears to be the cause. Just last week the Environmental Protection Agency issued a stop sale order to DuPont to immediately halt the sale, use or distribution of Imprelis, which had been widely used by professional landscapers.

According to the EPA, it’s the active ingredient aminocyclopyrachlor which may be causing the damage to certain species of evergreen trees. The herbicide is used to control broadleaf weeds, woody species, vines and grasses.

Check in with the EPA’s Imprelis resource page for more info on their investigation.

Credit: EPA News Release