Via Community News Service, a University of Vermont journalism internship
BURLINGTON — A wide variety of trees frame the sidewalks of Burlington, providing both beauty and environmental benefits. Urban trees help lower the temperature in cities, sequester carbon to help with climate change and can even help economically by raising property values and shading buildings to lessen the need for cooling.
City trees face many challenges, though, ranging from invasive species to climate change and road salt. One invasive insect recently threatened these urban forests, the term generally used to describe trees planted along streets and in parks and other spaces. That species is the emerald ash borer.
“We knew it was imminent,” said VJ Comai, the Burlington city arborist.
Emerald ash borers kill ash trees within a few years of infestation. That prospect was bad news for Burlington, where ash trees represented about 9% of the trees planted by the city in Burlington’s green belts, according to Comai.
The insect was first confirmed in Vermont back in 2018. It was a countdown after that until it reached Burlington. Treatment for emerald ash borer infestation is both expensive and maintenance-heavy, so the city decided replacement was a better option.
“I looked where our ashes were and I saw space,” Comai said. In preparation for the infestation, the city began planting a variety of species of young trees around the ash.
The first reports of emerald ash borer in Burlington came in July of 2024, to no one’s surprise. But the city was ready.
“We had already planted replacements for 70% of the ash trees,” Comai said.
Moving systematically, Comai and his team began removing the ash last fall and continued removing trees in 2025.
There were several areas in Burlington where the trees were too close together to plant replacement trees prior to the ash removal. To combat that, Burlington has already planted 168 trees this fall to replace all of the ash removed.
“There were 34 ash trees on North Union Street removed in June,” Comai said. “We have been able to plant 31(or) 32 replacement trees of a dozen different species.”
Diversity is a big aspect of urban forest resilience. As climate change occurs, various tree species are exposed to new harms. Planting a variety of species makes it less likely that climate change or a major event like emerald ash borer infestation wipes out Burlington’s tree canopy.
That’s not an idle threat. Burlington, like many communities around the country, lost the canopy of American elms that arched over city streets when Dutch elm disease infected the trees, with many of them cut down in the 1950s and 1960s. Another blow to the city’s urban forest came not from an infestation but from the ice storm of 1998, which toppled many trees.
Sometimes thinning the city’s urban forest, at least temporarily, is a necessity. Dead trees are a liability. Trees grow over sidewalks, houses and around people and a fallen tree can be dangerous. Burlington’s city tree team strives to remove dead trees from city property quickly and replace them within a calendar year, according to Comai. When many trees have to be replaced at the same time due to an unexpected event, it can be hazardous and costly.
Branch Out Burlington! helps the city grow its urban forest. The 30-year-old nonprofit organization operates a nursery at the University of Vermont Horticulture Research Center in South Burlington and has planted 2,570 trees in total over the years. The city of Burlington buys the trees and Branch Out Burlington! grows them in the nursery until they are strong enough to survive being planted in an urban environment.
The Branch Out Burlington! nursery acts as a testing ground for species before they are planted along city streets and in parks.
“If they die (at the nursery), that was a great experiment. If they thrive, we’ve established they can survive with all the variety and inconsistencies of our precipitation and climate,” said Jacob Holzberg-Pill, president of Branch Out Burlington!
The majority of the nursery’s trees arrive by truck from Oregon each April.
“We grow them for two, three, sometimes four years until they’re a nice big size and then the city arborists come and dig them up and plant them out on the street,” Holzberg-Pill said.
Vermont is a heavily forested state, with about 78% of the landscape, or 4.6 million acres, covered. Still, even in a state with abundant forestland, the urban forests in the state’s more developed areas can play an important role.
Vermont is using these urban trees as a strategy to combat environmental harms such as heat island effect, when urban areas are hotter than the surrounding land. In 2017, the Vermont Urban & Community Forestry Program at the Vermont Department of Forests, Parks and Recreation began collaborating with Vermont’s Department of Health to identify where heat island effect is impacting Vermonters to best aid in preventing the problem.
“We were looking at places where there are higher incidents of heat-related illness,” said Elise Schadler, program manager at the Vermont Urban & Community Forestry Program. “Trees provide shade and also transpire water vapor, so they help bring down the urban heat island effect. The co-benefit of that is that if you strategically place trees on a property to shade a building or to block wind, you can lower costs around heating and cooling and have less emissions,” she added.
Schadler and her team have been working to spread the benefits of urban trees throughout Vermont.
“Out of our 252 towns, there are only four towns that have a city arborist who has been trained, has the expertise, has the capacity and specific job duties of caring for the urban forest,” she said.
Most towns in Vermont use volunteers.
Two years ago, the Vermont Urban & Community Forestry Program was able to hire an urban forester to provide statewide resources such as videos showcasing proper planting techniques.
“When I started urban forestry,” Schadler said, “I was told street trees live 10 years. That has completely shifted. Now the message is that if you plant the tree the right way, prioritizing soil volume and rooting space, you can have a long lived tree.”
The future of urban forestry in Schadler’s eyes lies in the 3-30-300 rule. Vermont’s not there yet but it’s making progress.
“The idea is that every person in the world should live in a place where they can see at least three trees from their window, they live in a community that has at least 30% tree canopy cover and they live no more than 300 meters away from a park or a public green space,” Schadler said.