By Scott Taylor,Staff Writer

A tree fungus in southern and central Maine is shearing leaves from maples, leaving them looking dead.

It looks worse than it is, said Lewiston City Arborist Steve Murch. The trees should have new, healthy leaves returning in about a month.

“My biggest fear is that people are just going to cut down a healthy tree,” he said. “Don’t do it.”

The culprit is maple anthracnose, a fungus that thrives in wet conditions, said Clark Granger, plant pathologist for the Maine Forest Service. The fungal spores infect trees just as they bud. Eventually, the fungus eats away at the leaves.

The current outbreak is mainly attacking Norway maples, which are fatter and fuller at the bottom than other varieties.

“The tops of trees tend to be drier, thanks to the wind,” Murch said. “Little fungal spores have a harder time sticking up there. So trees with the low, full branches tend to be more susceptible. They give the fungus a better chance to hang on.”

Murch has also seen infected sugar maples, but the problem likely won’t affect next spring’s maple syrup harvest, Granger said.

He began getting reports last Friday from people in Gorham and Wells. Since then, he’s received about 20 calls a day from property owners and arborists. They’ve come from all other parts of the state, including Falmouth, Lewiston, Rockland and Bangor.

Murch got his first call on Monday. At first, he thought the damaged leaves were caused by overzealous lawn care.

“It looked like a chemical burn, like someone had sprayed fertilizer and killed the leaves,” he said. By Tuesday, reports began coming in from all over the city and he realized he was wrong. So far, he’s gotten about five calls a day.

Trees that were already sick could be killed by the fungus, Murch said, but healthy trees should recover easily.

“If they looked healthy last year and had good leaves this spring, they should be just fine,” he said. “The leaves will come back. They’ll refoliate and do what they need to survive.”

Maples are not the only leafy trees that can be harmed by the fungus. Granger expects similar problems among ash trees in the next few weeks.

Tree owners should rake away the infected leaves. That won’t help the tree get better now, but it could forestall future outbreaks.

“It won’t stop it, but it reduces the likelihood,” he said. “Fungus spores are pretty small and they can cling to anything. But clearing away the infected leaves can’t hurt.”

Maple anthracnose
What it is: A fungus that is infecting Norway maple trees from Wells to Bangor.

What it looks like: Trees appear dead, with blackened or blotched leaves.

What to do: Remove any fallen, infected leaves to cut down chances of fungus returning next year. Infected trees are not dead and will recover later this summer. Fungicides and sprays won’t help because it is too late in the growing season.

Source: Maine Forest Service