Minneapolis and St. Paul finished removing public ash trees

Fifteen years after the discovery of emerald ash borer beetles in Minnesota, the cities of Minneapolis and St. Paul have completed the removal of threatened ash trees on public property.

Emerald ash borers are insects that infest and kill ash trees, first discovered in Minnesota in 2009. They have spread widely, threatening the state’s estimated 1 billion ash trees, one of the largest concentrations of the trees in the nation. Most of them are located in forested lands, though tens of thousands were in the Twin Cities.

If left untreated, these infestations could devastate the entire ash canopy, said Rachel Morice, community forest project specialist for the Minnesota Department of Natural Resources.

So far the process has cost the two cities more than $50 million combined. St. Paul is turning its focus to publicly owned woodland properties and Minneapolis to ash trees on private lands.

In St. Paul, the last boulevard ash tree was removed on June 4, marking the end of its Structured Removal Process, said Rachel Jongeward, St. Paul’s urban forester supervisor. The city removed 26,947 trees in the past 15 years and is projected to have spent more than $36 million on emerald ash borer impacts by 2025.

There are still some ash trees in St. Paul. The city treats 112 ash trees in parks. Additionally, community members pay to treat 832 trees on public property.

Many ash trees also remain in St. Paul’s wooded areas. The city is focusing on their removal to protect maintained spaces. Controlling already infested areas is crucial to slowing the spread of the emerald ash borer, Jongeward said.

St. Paul does not condemn ash trees on private property unless they pose a threat to neighboring areas, she said.