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Chemical applications to fight ash borers beginning in Janesville

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Marcia Nelesen
June 19, 2013

— The Janesville Parks Department is applying chemicals this week to protect up to 200 ash trees as the emerald ash borer continues its spread through the city.

The state Department of Natural Resources estimates the city owns about 15,000 ash trees, half of which are in developed areas. That does not include another 15,000 on private property.

Insect-infested trees recently were identified by city staff in three new locations. The borer was first found in June 2012 near Craig High School.

The insect has all but wiped out ash trees in several states and has continued to spread across the nation.

Many cities first infested chose to cut all trees to get ahead of the bug, figuring the insect eventually would kill them, anyway. Some experts now say treating trees with chemicals might be more cost effective.

Chemicals do not have to be applied every year and probably even less often as the bug population declines after the infestation peak.

Milwaukee, for example, has decided to treat its trees rather than cut them, said Tom Presny, Janesville parks director.

But Milwaukee has a forestry program that is perhaps 100 years old and has community support to spend the millions of dollars it will take to chemically treat the trees, Presny said.

The parks department in Janesville earlier this year cut about 80 ash trees to test the cost and to educate residents about the bug, Presny said at the time.

Presny said workers chose those trees because they were in poor condition or growing into utility lines. The insect was not found in any, and some residents were shocked that the city cut mature and healthy trees in visible locations, such as Upper Courthouse Park.

Now, the city has hired K&W Greenery, the low bidder, to chemically inject up to 200 trees for $5,815. The cost per tree depends on the tree’s diameter and the amount of chemical needed, Presny said.

Trees smaller than 14 inches in diameter can be treated in other ways, such as soil drenches or basal bark sprays, he said.

Prensy said he has to study whether certifying a city employee to apply the chemicals is a cost-effective option. He said he would have to compare the worker’s hourly rate and the city’s learning curve compared to a contractor’s level of efficiency.

“You would perceive that could be more cost effective,” Presny said. “At the moment, we have nobody that is certified.”

Presny said he and Scott Schilling, a parks employee with a forestry degree and president of the Janesville Shade Tree Advisory Committee, chose the trees to treat. They focused on healthy trees with no sign of the borer in high-use areas with well-balanced tree populations.

“There’s far more trees than we have funding for,” Presny acknowledged.

“We try to find those areas where the shade or the aesthetics of the tree provide better value,” Presny said.

They chose trees close to park facilities, fields and playgrounds.

Workers will nail yellow tags to trees that are treated.

The first infected trees were found near Eastwood Avenue north of Craig High School.

About a dozen infected trees have been verified in three additional locations:

-- Wright Road and Milwaukee Street near Mercy Clinic East.

-- East Milwaukee and East Court streets.

-- Center Avenue and Riverside Street near Monterey Park.

One of the infected trees is a public tree.

Presny said staff did not find the new infestations because they were looking for them but because the trees were obviously stressed.

Signs include die back in the tree canopy and sprout growth at the tree base, Presny said.

A tree usually cannot be saved if more than 40 percent of the tree has died, he said.

The Janesville City Council in its 2014 budget set aside $107,000 to deal with the ash borer infestation.

During budget discussions, Presny asked for money to hire a forester or contract with an arborist.

The council gave him $25,000 to contract with an expert. Presny said he has not yet done so.

When the insect was first identified here, Presny said he heard thousands of trees would be infected within three years.

The city has learned from other communities that the spread of the disease “isn’t quite that accelerated,” he said. Infestations grow along a three- to five-year curve before really taking off, he said.

“There is a point in time where a consultant ... will be needed and will be hired,” Presny said. “In the next 30 days, or late this year, or early next year, I don’t have an answer.

“At this moment, I haven’t felt the need,” he said.

“My awareness is: ‘We have a problem,’” Presny said.

“My lack of awareness is: ‘How expansive is the problem, and what would this consulting forester actually accomplish or actually do?’”

Presny hired a forestry college intern this summer for 20 hours a week at $8 an hour. That comes from money outside that budgeted for the ash borer.

Experts interviewed by The Gazette said the first thing a city should do is create a tree inventory so it knows where they are and can decide which to save.

Presny agreed an inventory is valuable but said he has yet to do one because it is time consuming and costly.

“Most communities have dedicated software and forestry staff to complete the inventories,” Presny said.

How Janesville continues to deal with the ash borer is a question of cost for the community as staff continues to identify the expense of programs, he said.

“The treatment process will educate us as to what we accomplished and perhaps what we overlooked,” Presny said.



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