MECAN members Mallory and Birkel explain effects of climate change on planting dates in Maine
Farmers and gardeners who feel like Maine’s growing season is changing are right. And soon, the state’s hardiness zones will reflect that. It’s just a question of when.
“Our average annual temperature has increased by about three [degrees Fahrenheit] over the last century, and is expected to increase an additional two to three [degrees Fahrenheit] over the next 50 years,” said Ellen Mallory, extension specialist and professor of sustainable agriculture at the University of Maine. The winter minimum temperatures are increasing even faster than the average annual temperatures, Mallory said. Those are what’s used to determine hardiness zones.
Sean Birkel, research assistant professor and state climatologist at the Climate Change Institute and School of Earth and Climate Sciences at the University of Maine, said that though there is “quite a bit of variability year to year,” the statewide growing season on average has increased “by approximately two weeks [total] since 1950.”