Norway maple leaves are falling early. Blame a fungal disease

Norway maple leaves are falling early. Blame a fungal disease

WXXI News |
By
Beth Adams
Published August 27, 2026 at 3:35 PM EDT

It’s not even September, but the leaves on many maple trees across upstate New York have been turning brown and falling

A leaf disease called “tar spot” is infecting Norway maples this summer. Tar spot is a fungus that is not fatal to a healthy tree, but it does cause an infected tree’s leaves to develop round, black spots and eventually turn brown and fall off weeks before autumn

“We’ve had an awful lot of tar spot this year because it was really wet in the spring, which made the perfect conditions for the spores of this fungus to spread around,” explained Tim Wenskus, Finger Lakes regional forester for the New York State Department of Environmental Conservation

As he walked along the side of the road in a western Irondequoit neighborhood on a warm August afternoon, Wenskus pointed to the tree canopy above

“If you look up at the crown, you see they’ve already lost half their leaves,” he said

Brown, dry leaves covered the ground. Norway maples, he said, are a durable species. They just happen to be susceptible to this particular blight

Here’s the good news: Tar spot isn’t fatal. It just robs trees of their green summer leaves and their future fall colors. To keep that fungus from spreading again in the spring, Wenskus recommends getting those brown leaves off your lawn and not using them for mulch

“If the leaves are just sitting underneath your tree all winter long, then come springtime, the fungus only has 10 feet to go to get back into your tree again,” he said. “Whereas if the infected leaves are off your property, the fungus is going to have a lot harder time coming back.”