New herbicide being blamed for dying trees

New herbicide being blamed for dying trees

Posted 20 July 2011, by Carol Hopkins, The Oakland Press (Journal Register MI),

(from left) Mary Hardenburgh and Peggy Holtzclaw, residents of Scott Lake Coves condominiums, next to one of the 34 dead pine trees in the complex in Waterford Twp., pictured Wednesday, July 20, 2011. (Oakland Press Photo: Vaughn Gurganian)

As attorneys begin filing lawsuits over a new herbicide supposedly caustic to pine trees, Peggy Holtzclaw sympathizes with people who have watched their own trees turn brown this summer.

Holtzclaw, who lives in the Scott Lake Coves condominiums on Scott Lake Road, has counted more than 45 pine trees with rusty-colored needles.

“I’m very passionate about trees and plants. This spring (our blue spruces) were green and lush, with new growth,” said Holtzclaw, secretary of the condo association.

Besides adding to the ambiance of the property, the pines provide privacy, said Holtzclaw. “This,” she said, gesturing at the browned-out trees, “is just killing me.

Holtzclaw said a herbicide called Imprelis applied by professional landscapers is being blamed for the trees’ problems.

The herbicide, used to control tough, broad-leaf weeds, is causing problems around the country, said Bert Cregg, Michigan State University associate professor of Horticulture and Forestry.

“We’ve been taking a lot of calls,” said Cregg.

Imprelis works by interfering with a plant’s normal hormonal balance, according to MSU officials. It is sprayed onto surfaces and taken in through a plant’s foliage as well as through the roots.

Cregg said the herbicide is being scrutinized from Iowa to the East Coast. On Wednesday, The New York Times reported that a Pennsylvania homeowner and an Indiana golf course company have filed a class-action lawsuit against DuPont in U.S. District Court for the District of Delaware charging that the chemical giant was either negligent or reckless in putting a new weedkiller on the market. A similar lawsuit was filed on Friday against Dupont by a golf club in Michigan that has reported thousands of dead and dying trees on its properties, according to The Times.

The tree damage happens quickly, within two to three weeks of application.

“We are taking this very seriously,” said Kate Childress, Dupont spokeswoman.

“We are working with our customers to understand the situation and make sure appropriate action is taken.”

Childress said Imprelis is still on the market but added, “The season for application has passed.” Professionals were instructed in mid-June to not apply the herbicide near Norway spruce or white pine trees, she said.

A dedicated gardener, Holtzclaw, a Scott Lake Coves resident for a decade, said the herbicide was applied this past spring and that the first browning on one pine was seen in May.

“By June we knew some new growth was turning brown and we called for help,” she said.

The professional landscapers, not named by Holtzclaw, said the trees were in stress and that they had received a faxed letter from Dupont, the herbicide’s maker, saying the company was investigating reports of damage.

Cregg said people were “excited” about Imprelis because it was not toxic to humans or animals.

“It looked like it was going to be a good product,” he said.

Dr. David Roberts, senior academic specialist with MSU’s College of Agriculture and Natural Resources, has visited areas in Michigan with affected trees.

“Some will come back and some are dead,” said Roberts.

People are going to have to take a “wait and see” approach, he said.

Dupont did “quite a bit of testing,” Roberts said.

But this year’s wet spring could be a crucial factor.

“The rain moved (Imprelis) into tree root zones,” he said.

“That happened at sites I saw.”

Cregg recommends giving the trees water every third day, especially in the current heat wave.

“You don’t want to waterlog it,” he said.

“Trees are living, dynamic organisms with a certain amount of resiliency. Even trees that have a lot of damage are still alive.”

Gary Eichen, plant health care manager at Mike’s Tree Surgeons in Troy, said his office began getting the calls in June from people in Troy, Birmingham and Rochester Hills.

“The herbicide is a growth inhibitor and that’s what it’s doing to the trees,” said Eichen.

Eichen didn’t recommend changing watering habits.

“I would be afraid of moving (the herbicide) to where more roots are. I definitely would not fertilize. I think most will recover over two to three years.”

The Times story indicates the Environmental Protection Agency is investigating the reports of tree deaths.

The Waterford trees, some nearly 20 feet tall, on south side of the condo property have been affected more than those on the north, said another resident, Bob Kent.

“They’re in varying stages of distress,” said Holtzclaw, who estimated the cost of replacing one might run $2,000 to $3,000.

“We don’t know who is liable, Dupont or the tree service.”

Holtzclaw said she doesn’t go out on her deck much nowadays, she said.

“It’s just sad,” she said.

Contact Oakland Press staff writer Carol Hopkins at Follow her on Twitter @waterfordreport.


The herbicide Imprelis is being blamed for pine tree browning. According to MSU, Dupont is warning customers not to apply Imprelis where Norway spruce or white pine trees are present or close to the property to be treated. To learn more about Imprelis, visit


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