Editor's note: This story appeared in the October/November 2024 issue of Arboretum Magazine.
As Minnesota’s climate changes, forward-thinking gardeners and city managers are planting trees that can handle the impacts of climate change. According to the State Climatology Office, average temperatures across the state have risen by 3 degrees since 1895. Minnesota has also seen a significant increase in extreme rainstorms, particularly in the past two decades.
As temperatures rise and more frequent extreme weather events occur, familiar Minnesota tree species that shade backyards and line city boulevards might not be the best adapted to these changes.
Trees provide myriad ecological and socioeconomic benefits for neighborhoods and cities: They sequester carbon, provide habitat (and sometimes food) for wildlife and cool homes and cities with the shade they provide. On sunny days, mature shade trees decrease the pavement temperature by up to 30 degrees and reduce home cooling bills by up to 25 percent.
“If you’re a homeowner, trees are the only infrastructure that grows in value year over year. Planting climate-resistant trees means they will live longer, grow larger and increase your property value over time,” said Arboretum arborist Ian Vaughan. Planting trees that are well-adapted to the changing climate ensures that future generations will reap these same benefits.
While climate change threatens some beloved Minnesota tree species, there are plenty of amazing tree options that experts expect to thrive in the coming years. Many of these have wide native ranges across the eastern U.S., but may be new to Minnesota gardeners. There are many to choose from, but here are five favorites visitors can find at the Arboretum.
Hackberry
Celtis occidentalis
In places where Dutch elm disease has wiped out American elms, some people are replacing elms with the native hackberry for its similar leaves, size and shape. My favorite trait is its ability to handle both flooding and drought. You may ask, how can a tree be adapted to both droughts and floods? It might be because the hackberry is native to floodplains where water levels constantly go up and down. In the fall and winter, the edible berries support fruit-eating birds and small mammals.
Swamp white oak
Quercus bicolor
I’m a big fan of oak trees, and the swamp white oak is a favorite for its naturally crooked branch structure and broad, inviting canopy. This Minnesota native tree is expected to thrive in our changing climate thanks to its tolerance for heat, flooding and drought. Because oaks are long-lived and need a lot of space to spread their roots, plant them far away from pavement, powerlines or waterlines.
Kentucky coffeetree
Gymnocladus dioicus
While this species is native to northern Kentucky, it is also found in southern Minnesota. It withstands hot and dry summer weather, which is good news for Minnesota gardeners as we continue to see more 90-degree days. It is often planted along parking lots and boulevards since it handles poor soils and heat radiating from pavement. If its showy, large seed pods are a deal-breaker for your site, try the University of Minnesota-developed ‘Stately Manor’ cultivar, which is seedless.
Shagbark hickory
Cladrastis kentukea
I learned to love this massive nut tree as a camp counselor in Iowa, where old hickories stand tall in the woods along the Des Moines River. Once mature, this tree features “shaggy” peeling bark, and the nuts are edible. Native across the eastern U.S., shagbark hickory handles warmer winters and summers, periodic droughts and flooding. Several other, less-hardy hickory species such as mockernut, black and pignut hickory are slowly moving north into southern Minnesota as winters get warmer.
Yellowwood
Carya ovata
For smaller spaces, consider the yellowwood tree, which tops out around 30 feet tall and produces fragrant white blooms that feed pollinators in the spring. While native to the southern U.S., it has proven hardy enough for Twin Cities winters. Once established, it can withstand periods of drought and heavy rainfall, making it a climate change-ready tree option for Minnesota.
Other climate-ready trees recommended by Arboretum experts include ironwood, tulip poplar, bicolor oak, eastern redbud, katsura tree, northern catalpa and bald cypress.
As I walk around community parks in the Twin Cities metro, I feel hopeful. City managers see the need for diverse trees that will thrive in the coming years and provide benefits for future generations. You can help by planting a tree for the future in your own yard. Visit z.umn.edu/climate-ready-trees to hunt for these trees at the Arboretum and learn about more climate-ready trees.