Across central and northern New York, leaves are falling from trees a few months earlier than usual. But it doesn't mean an early start to autumn. A pair of fungal diseases are bringing an early look of fall to one particular species of maple trees.
Don Leopold, a tree expert at SUNY ESF in Syracuse, doesn’t have any Norway maples on his property. But the fast growing invasive species is common in his neighborhood. And he’s been finding evidence of fungal diseases that have been attacking these trees for weeks now.
"I've been picking up leaves from the neighbor's Norway Maple for over a month now," said Leopold. "And it's like somebody just threw a bunch of brown paper, it's like somebody's littering every single overnight on the road."
You can tell a Norway maple is being attacked by a fungal disease in a few ways.
"The one that's most noticeable is the tar spot," Leopold said. "When the leaves fall and they're not crumbled up, you can see these big blackish spots almost like it with a little ring around them. But a lot of the leaves are crumbling from another disease called Anthracnose."
Most years the tree canopy stays in place until late October or early November. But because of Anthracnose, which developed because of a cool, wet spring, the leaves started falling off these trees starting in July.
"The two diseases together are pretty profound and most of the trees in central New York are defoliated or in the process of losing all their leaves," Leopold said.
These diseases won’t kill the Norway maples, said Leopold. But they do create an unattractive fall palette. And if your goal is a healthier tree canopy, his advice is get rid of the Norway maples that have no redeeming qualities and are also the most invasive woody species in the Northeast.
"In upstate New York, there are literally a thousand different tree species that you can plant," he said. "Every one of them better than Norway Maple, small or big or whatever. And so why not think about maybe changing our landscape? This would be a great time to think about it."
