'Moisture stressed' trees will likely produce less vibrant fall foliage this year

New England's fall foliage “may be a little different than a typical year” after a rainy summer, according to forestry experts.

Nicole Keleher, the forest health program director at the Massachusetts Department of Conservation and Recreation, explained the trees are “moisture-stressed” as the result of excessive rain in the area. “[For trees], much like being too dry can be too stressful, being too wet can be a little bit too stressful,” she said.

That stress will likely affect the leaves: how their colors transition and how long they stay on the trees.

Extensive rainfall caused flash flooding in Vermont and parts of western Massachusetts in July. And along with Providence, Rhode Island, and Worcester, Massachusetts, Boston experienced its second-wettest July on record this year.

All that rain means thriving mushrooms and fungus.

“As [the trees] go through that [autumn] color change… you'll see more leaves that have brown or black spots on them, or look a little curled or discolored from funguses that have been growing and feeding on the leaves," says Keleher. “But the biggest impact is how long the leaves last.”

For example, a healthy oak tree may have its leaves change color and hang on through spring. But a moisture-stressed maple leaf with some fungus might turn red or purple and drop earlier in the fall.

The Old Farmer’s Almanac projects much of New England will be at or near peak fall color by Oct. 11.

Despite fungal growth, Keleher said she expects beautiful foliage: “In Massachusetts and in New England, we always have great foliage, even in years where it's not like the best year. It's still beautiful. And it's still always amazing to see.”