An Indianapolis-based golf course manager is leading a national class-action lawsuit charging that a herbicide manufactured by DuPont is killing trees and other vegetation.

R.N. Thompson Golf LLC, which operates several area courses, including Gray Eagle, Ironwood, Winding Ridge and Southern Dunes, said it has witnessed "catastrophic tree loss” after applying the herbicide Imprelis.

The two law firms representing the class-action suit, Lieff Cabraser Heimann & Bernstein LLP of San Francisco and Starr Austen & Miller LLP of Logansport, announced the filing in a federal court in Delaware on Monday.

Their complaint alleges that Delaware-based DuPont failed to disclose the risks Imprelis poses to trees, even when applied as directed, and failed to provide instructions for safe application.   

Mario Massillamany, a lawyer at Starr Austen, estimated the damages to RN Thompson’s golf courses to be “hundreds of thousands of dollars.”

R.N. Thompson began using the herbicide in late April and began noticing signs of destruction about a month later. Most of the heavy damage has occurred at Winding Ridge in Lawrence, where between 130 and 160 trees have died since Imprelis was applied, Massillamany said.

Trees have also suffered damage at Southern Dunes in Indianapolis and at Gray Eagle and Ironwood in Fishers.
 
“I don’t think there’s any way to stop the destruction,” Massillamany said. “Once it starts, it’s over.”

Lawyers said they’ve engaged a leading scientist in the fields of forest resources, tree physiology, and landscape management to further identify the cause and nature of the problem, and to recommend steps property owners should take to preserve evidence.

“Even though it’s a new product, Imprelis has been widely adopted by landscapers and lawn-care specialists who believed DuPont’s claims that it is safe and an environmentally friendly herbicide,” said Jonathan Selbin, a lawyer at Lieff Cabraser, in a prepared statement. “Instead, the evidence is quickly piling up that Imprelis is attacking trees as if they are weeds.”

R.N. Thompson CEO Mark Thompson said the company has received numerous complaints and inquiries about the tree damage and appearance of its courses from customers.

“We filed this lawsuit to inform other businesses and homeowners about this problem to let them know there is reason their trees are dying and to give them a course of action to fix the problem,” Thompson said in a written statement.

R.N. Thompson is joined as a leading plaintiff in the lawsuit by a Pennsylvania homeowner who claims trees in her yard died after she sprayed the herbicide.

Plaintiffs are seeking compensation for the cost of replacing damaged trees and an injunction preventing DuPont from continuing to sell Imprelis.
Dupont began selling Imprelis last November as a high-concentration herbicide that kills tough-to-control lawn weeds such as clover and the vine known as "creeping Charlie." Imprelis costs about $750 per gallon, but it only takes about 4.5 ounces to treat an acre of lawn.

In mid-June, DuPont responded to mounting complaints about the use of Imprelis, saying: "Our turf development team has been investigating these reports and we are trying to better understand the circumstances and whether the various symptoms are related to applications of DuPont Imprelis herbicide. Our investigation is not complete and we will need your help in gathering necessary information and in determining what variables may have contributed to the symptoms being observed.”

A majority of the damage involves Norway spruce or white pine trees, which are common on golf courses. As a precaution, DuPont instructed users to avoid applying the herbicide where those types of trees are present.