State officials and lawn care professionals say they think Imprelis, an herbicide introduced last year for commercial use by DuPont, may be attacking pines and spruces as if they were weeds.
© Martha Thierry/Detroit Free Press
So many trees have died -- from the East Coast west to Iowa -- that the damage is projected to be in the millions of dollars, and now many states and the U.S. Environmental Protection Agency are investigating the possible link to Imprelis.
Amy Frankmann, executive director for the Okemos-based Michigan Nursery & Landscape Association, said she has not seen such widespread tree damage since the emerald ash borer decimated the state's ash trees.
"I'd say this is right up there as far as the significance and losses," Frankmann said.
Tree damage likened to emerald ash borer infestation
Mark Underwood says he thought he was doing the right thing, both for his family's lawn-care business and the environment, when he switched to Imprelis, a new herbicide.
But a month after crews from his Adrian-based Underwood Nursery sprayed the DuPont weed killer on hundreds of lawns in southeast Michigan, the calls began.
"The customers are calling: 'My trees are dying, what's up?' " Underwood said. "We've never experienced anything like this."
In what some say could be one of the biggest disasters of its kind since the emerald ash borer killed millions of trees, white pine and Norway spruce trees are turning brown or dying all around the country. Tree damage has been reported throughout the Midwest, in East Coast states and as far south as Georgia.
No one can say with certainty what's causing it, but many lawn-care professionals and state officials suspect Imprelis, which the U.S. Environmental Protection Agency approved last year. The chemical is supposed to kill such weeds as dandelions and clover, which absorb it through their roots and shoots.
Tree damage, though, is so extensive that the EPA hosted a teleconference Wednesday with departments of agriculture from several states to gather information about a possible link between Imprelis and the trees.
The Michigan Department of Agriculture and Rural Development is studying sites of damaged trees and gathering samples of wood and soil. Michigan State University Extension is monitoring the situation and also has visited sites following complaints from landscapers.
DuPont, the chemical giant based in Wilmington, Del., began investigating the problem last month. In a June 17 letter addressed to customers, Michael McDermott, global business leader for DuPont Professional Products, said Imprelis, which is sold only to professional landscapers, may not have been mixed properly or was applied with other herbicides.
Until more is known, he urged customers not to apply Imprelis near Norway spruce or white pine.
Calls to the EPA's regional office in Chicago, which coordinated a conference call on the tree damage with officials in several states, were referred to the Washington, D.C., office. An agency spokesman said he would get back to the Free Press but did not.
Although the problem is only months old, landscapers could be in trouble if their insurance companies don't pay and they are on the hook for replacing trees.
"I'm getting calls almost daily from landscapers or the landscapers' insurers," said Bert Cregg, an associate professor in MSU's Departments of Horticulture and Forestry. They ask, 'Who's liable here?' and those kinds of questions. It's really a big mess."
Kate Childress, spokeswoman for DuPont, declined to say how many complaints the company had received.
"We're taking this seriously," she said. "We're very committed to understanding the circumstances and what caused the unfavorable symptoms" in the trees.
Is Imprelis damaging trees? "I'm not in a position to say yes or no," Childress said.
"We do recommend everyone keep records and document everything," she said.
She said Imprelis underwent 400 tests conducted at various universities as to its effectiveness, toxicity and other factors.
"Imprelis has a very favorable environmental profile," Childress said, "which is why we do remain excited about the product."
David Gardner, an associate professor in the Department of Horticulture and Crop Science at Ohio State University, said he has been testing Imprelis on weeds. Since 2006, he has done 32 field studies including varying formulations of the herbicide.
"Millions of dollars worth of research goes into getting these products registered," Gardner said.
He said DuPont is very concerned about the complaints. "I know they're spending day and night trying to figure out what's going on."
Investigators puzzled
Brian Rowe, pesticide section manager for the Michigan agriculture department, said his office is investigating about four complaints of browning or dying trees.
The state doesn't have the resources to check every property involved, though. Rowe said that in one case, a landscaper contacted his office saying that he had more than 600 customers and 160 of them had damage.
State investigators check to see whether landscapers followed proper directions and ask for copies of records of applications of Imprelis. The state also is in early discussions with DuPont, Rowe said.
"It's not very common we see something like this on this large a scale," he said.
Officials are puzzled.
Some landscapers appear to be following directions and spraying Imprelis away from the trees, but they still have browning, Rowe said.
In some cases, some white pines and spruces turn brown while others of the same species don't, despite being in the same yard.
In the Brookview Highlands subdivision in Pittsfield Township, at least 100 trees look diseased or dead. Many of those homeowners had contracted with Underwood.
Teddy Peace, who lives on Windmill Way, said eight of the 50 trees on his property have damage. "It just kind of hurts because the trees are old and beautiful, and you hate to see them die," Peace said.
He expects Underwood to make good on a promise to replace the trees or suffer consequences.
"We're ready to take further action," Peace said. "We hope we won't have to do that."
Down the street, Kristen Huber saw a change in her evergreens.
"At first, everything had this huge flush of new growth, and two weeks later, it was all dying," Huber said.
Curtis Magleby, who lives on Highridge Circle, said he has three dead and five damaged trees. He first thought it was a disease, pine wilt, but then learned of neighbors' problems after Underwood applications.
"There's no reason a 20-foot spruce should be taken down over one application on dandelions," Magleby said.
Diane Andrews, executive director of the Michigan Green Industry Association, said the problem showed up in Michigan later than in some other states because of the late spring and heavy rains.
Andrews said it could have been a lot worse. She knows that many contractors passed on Imprelis because it was too costly.
Steve Martinko, owner of White Lake Township-based Contenders Tree & Lawn Specialists, said he used Imprelis -- spending $1,100 a gallon -- but stopped after two trees were damaged.
"I wouldn't be able to sleep at night if I knew we were still using it," Martinko said.
at the lengths we will go to just to do away with a few 'weeds' that no one would even notice. If its green, it stays on my lawn and i treat it like it belongs there. We have undergone a 'chemical brainwash' by the major chemical corporations.