Wausau forester outlines emerald ash borer plan, planting grant and calls for closer coordination with engineering

Wausau City Forester John Kehan told the Parks and Recreation Committee on May 5 that the city has removed 1,695 ash trees tracked since about 2019 and is managing a large emerald ash borer (EAB) infestation with a mix of injections, removals and replacement plantings.

Kehan, introduced by Parks staff member Polly, said the city is following an updated EAB management plan and is working to keep removals and replanting on a steady schedule while using injections on selected trees to control spread and buy time. “We’ve taken down 1,695 ash trees that we’ve tracked since roughly late 2019,” Kehan said. “We had a vision we had about 6,000 ash trees. We’ve really had closer to 7,000 in the city.”

The committee learned that injections have been used in recent years to preserve certain boulevard ash trees: Kehan reported injections of 873 in 2022, 948 in 2023 and 742 most recently. He said the city’s inventory includes roughly 3,317 ash trees remaining that are being monitored and that about 806 of those are not currently on the injection list because they are small, in poor condition or poorly sited.

Why it matters: The EAB infestation is driving a multi-year program of removals and replacements. Kehan said the city’s pace aims for a 12-year removal-and-replacement timeframe to allow flexibility if schedules slip and to avoid being driven solely by the insect’s spread.

Plan, removals and plantings Kehan said the public-right-of-way removals have recently been about 800–900 trees per year, while current replanting is about 525 trees per year — leaving an annual shortfall of…