Central New Yorkers might be wondering why certain maple trees have withering and falling leaves in mid-August. While it may look like an early start to autumn, experts say it’s actually due to disease.
Leanna Nugent has a Norway maple in her yard in Solvay where spotted, withered leaves hang on the tree and cover the lawn.
“What we're seeing a lot in the area, especially with the Norway maples, is a mix of anthracnose and maple tar spot," she said. "Some trees have both, some trees have one or the other. My best guess, at least with my tree, is it definitely has the tar spot.”
She says anthracnose is not uncommon, but a wet spring and early summer made it especially bad this year. Nugent is a certified arborist and a Community Forestry Educator with Cornell Cooperative Extension of Onondaga County. She’s fielded dozens of calls from concerned residents, and tells them there is no cause for alarm.
“It's really more of a cosmetic issue than it's not going to hurt the tree at all," she said. "The tree should leaf out normally again next year. But I would recommend that people rake up the infected leaves and place them elsewhere so that the infection doesn't spread again next year.”
Nugent said Crimson King maples and Sycamores are also susceptible. While trees are not necessarily harmed, she adds being defoliated during growing season is problematic.
“This is the time that the trees are photosynthesizing, they're storing up their food for the winter," she said. "So taking away the tree's ability to photosynthesize is going to affect it. Just one season, not so much. But if we had maybe three, four, five years of this, that's when it starts to become a problem.”
Luckily, Nugent said, she hasn’t encountered that in her research.
People can learn more about tree fungus, biology, planting, pruning, and care through Cornell Cooperative’s Communitree Stewardship program. Registration is underway for classes next month that include hands-on field trips.
