Investigators have a suspect in the case of a string of spruce and pine tree deaths across the country—DuPont's Imprelis herbicide. The EPA approved limited sales of the herbicide, thought to be safe for the environment, last fall. However, reports of thousands of dying trees have led the company to warn landscapers not to use it around certain species, according to the New York Times.
Imprelis is used to control weeds like dandelions and wild violets, but the chemical is reportedly having adverse affects on trees—especially white pine and Norway spruce. "It’s been devastating,” says one nursery worker. "We’re seeing some trees doing okay, with just the tips getting brown, and others are completely dead and it looks like someone took a flamethrower to them.” (Read more Imprelis stories.)