This September, two Southwest neighborhoods tried a new treatment to help control Emerald Ash Borers.
A chemical — developed by Eagan-based Arborjet — was injected into 34 Ash trees in the Lowry Hill and Whittier neighborhoods. Specifically, 20 trees were treated on Pleasant Avenue and 14 on Dupont Avenue.
Emerald Ash Borers are currently a big threat to Minnesota’s tree population and a major headache to property owners. The small Asian beetles place their larvae below the bark of the tree. When the larvae hatch, the grubs eat the inner bark of the tree, essentially starving it to death.
Minnesota has more than 900 million ash trees, second most in the nation, according to the state Department of Natural Resources. That makes the state one of the largest at-risk for a full on Emerald Ash Borer infestation.
“We know it’s here,” said Rob Gorden, National Sales Director of Arborjet. “It remains hidden for a long time, when it attacks the outcome is death.”
Gorden said the company’s newest chemical is cheap and effective enough to be a viable alternative to removing infested trees outright.
“Our product has a 99 percent success rate in controlling the insects,” Gorden said. “Not only can we kill it, we found a city can treat a tree for about $53 and get themselves two years of protection.”
Ralph Sievert, director of forestry for the Minneapolis Park and Recreation Board, said such treatments prompt questions.
“It’s not so much about the worry whether it will work,” Sievert said. “Even if you have the money to do it, to what point would you do it on a big scale?”
Sievert pointed out that cities such as Milwaukee, which has started to use the treatment on a larger scale, are using the method merely to manage which trees to remove. The best thing house owners can do to help combat the Emerald Ash Borer is simple, he said. Plant a tree.
“Everyone benefits from a city canopy,” Sievert said. “The Ash Borer makes it a bigger deal to get trees planted on private property. The sooner you can plant a tree, the better.”
When Arborjet treats a tree, workers drill small circular holes around the base of the trunk. A small, plastic plug (called an Arbor Plug) is then inserted into each of the holes. The plastic plug has a rubber seal that helps keep the chemical from leaking out of the tree. Workers then inject the chemical into the tree through the rubber seal.
Arborjet treated the Southwest trees for free. Sievert said the treatment was not necessary, but it served as an important teaching opportunity.
“We kind of look at it more of like we provided the trees and they did the demonstration for the benefit of the residents,” Sievert explained.
“It costs $750–$1000 dollars to remove a tree,” Gorden said. “The city needs to see that removing trees is not a good option.”
He said a tree can be treated for 40 years before the cost equals the bill for cutting it down. The dollar value does not take into account intangibles like street appeal or utility bills.
Sievert said there is no need for immediate treatment in the areas of the demonstration.
“Right now, our infection is way over by Tower Hill Park,” Sievert said. “It’s almost as if the genie hasn’t gotten out of the bottle yet.”