NH fall foliage 2023: Why strong peak season is expected and where to enjoy it

You feel that cool crispness in the air on certain days already. You see the long shadows cast by the late-day sun earlier each evening. Around a low-lying wetland, you spot a red patch of leaves.

Those who have made studying New Hampshire’s trees their life’s work feel and see the signs of change, too, and they’re predicting a vibrant foliage season for the state this year.

“It’s a good canvas for all the colors to fill this fall,” said Steven Roberge, state forestry specialist for UNH Cooperative Extension. “We haven’t had any defoliation events. When I drive around the state, I see a canopy that is pretty well developed, pretty foliated, and overall pretty healthy.”

He readily dispels the notion that this year’s wetter-than-usual summer will affect the quality of the state’s foliage, noting the only weather that affects the fall foliage is the weather during foliage season.

“The best color comes from a healthy tree,” said tree physiologist Kevin Smith, who has worked for the U.S. Department of Agriculture Forest Service in Durham for 36 years. “So the best predictor of the fall foliage, in my opinion, is the trees being healthy at the onset of fall. And so far things look pretty good to me. Everything is shaping up to be a good season for foliage, and my basic recommendation is to get out and enjoy it.”

Foliage brings millions of people and billions of dollars to NH

New Hampshire is famous for doing just that. According to the N.H. Division of Travel and Tourism Development, last fall 3.5 million visitors came to join us in leaf peeping. While here, they spent $1.7 billion, making the foliage season a large contributor to the state’s economy.

Worries about this summer’s excessive rainfall affecting fall’s foliage and tourism are unnecessary, these tree experts say.

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Roberge said the wet weather in summer can play a role in increasing fungi that exist on trees, causing diseases like anthracnose, but he doesn’t think that will be a problem this fall.

Smith agrees. “Indeed foliage quality can be affected by leaf diseases. Anthracnose is one family of those diseases caused by fungi that hit maple and oak. They occur every year,” Smith said. “They affect different species at different times of the year. And moisture can help facilitate that.”

But, Smith said, he hasn’t seen any indication that anthracnose or tar spot, another disease, will be bad this fall, and he hasn’t seen any signs of moisture stress in the state’s trees.

Already the trees around us are getting the message that it’s time to prepare for winter. The shorter days and decreasing sunlight trigger “a pre-programmed set of instructions contained within the tree’s genetic code. It takes its cue from its environment,” according to Smith.

“With the amount of light the trees are experiencing now as the days get shorter, they start to curb their production of chlorophyll and bring it back into the stems, branches and roots,” Roberge said. “The leaves are shutting down as we speak.”

How the colorful leaves form

The yellows and golds of autumn are already in the leaves and are masked by the green of the chlorophyll. As it breaks down, the yellow pigments are left behind and become visible, according to Roberge. This is just the natural process of the tree and is not affected by any external factors.

“The yellows will pop out regardless of what happens in summer,” Roberge said.

External influences do bring about the reds and maroon colors of the fall leaves.

“The red colors we see are dependent on the weather occurring in the fall,” Roberge said. “Sunny, warm days and cooler nights create, develop and intensify these pigments and that’s how we get the brilliant reds, russets and purples.”

Smith said those brilliant colors come from “an orderly, sequential process in which the tree recovers as much of the good stuff in its leaves that it can, and then sheds those leaves. It’s part of the life strategy of the tree.”

When is peak foliage in NH?

Roberge said you can’t really predict when peak foliage will occur, but based on the timing of past years, he said, it usually happens between mid-September to late October.

“It’s usually a three-week period from late September through early October,” he said. “Then even after that it can continue with the magnificent red of oak foliage against the backdrop of the green of the white pines in late October. Oak is really good at holding onto its leaves.”

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Smith said the best color or peak foliage in the state is usually “a week either side of Indigenous Peoples' Day.”

Weather can affect the viewing of foliage, of course. “It’s how seeing the bright scarlet against a gray sky is different from seeing it against a bluebird blue sky, but both are wonderful,” Smith said.

Weather during foliage season can shorten it, Roberge said. “A lot of rain can knock the leaves off, or gusty winds, or a tropical storm. The trees are ready to lose their leaves,” he said.

Where are best places for foliage in NH, in Seacoast and in your town?

For viewing, Smith suggests “the old standard” Franconia Notch State Park, Sandwich Notch, Mount Kearsarge, Odiorne State Park, or the area around Little Boar’s Head in North Hampton.

“Even the walk from Prescott Park in Portsmouth over to Pierce Island can have nice color at the right time,” Smith said. “Any two-lane back road is beautiful. Get lost around Hopkinton and Contoocook. The mountains are great and most of my time in field research is up in the mountains, but you don't have to go there. It can be beautiful anywhere.”

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He urges New Hampshire residents to get out and enjoy the foliage, even if it’s just when you go to the post office or grocery store.

“Take a deep breath. We live in a beautiful part of the world for foliage, and we should take advantage of that,” he said. “Especially in northern New England, we are so favored by having this diverse mix of hardwood species like maples, birch, beech and aspen, and that combination is part of what makes the New Hampshire landscape special.”

Roberge agrees the state is lucky in “the diversity of its elevations and foliage types.”

“We are so lucky with the New Hampshire landscape running south to north, from the Seacoast to the treeline, that allows us a diversity of fall foliage for weeks,” Roberge said. “As I travel the state, every year I’m impressed at its magnificence. I encourage everyone to experience it.”

Keep tabs on the fall foliage in N.H., Maine and beyond

Here are some resources for keeping track of the progression of this year’s fall foliage:

Weekly New Hampshire foliage reports: visitnh.gov/seasonal-trips/fall/foliage-reports

NH foliage tracker: visitnh.gov/seasonal-trips/fall/foliage-tracker

Predicted peak foliage for regions of New Hampshire based on historical data: visitnh.gov/seasonal-trips/fall/peak-foliage-map

New Hampshire foliage trip planning, suggested driving routes: visit-newhampshire.com/state/foliage

Weekly Maine foliage forecasts and road trip information: maine.gov/dacf/mfs/projects/fall_foliage/index.shtml

Old Farmer’s Almanac foliage map: almanac.com/fall-foliage-color-map-when-peak-foliage

This article originally appeared on Portsmouth Herald: NH fall foliage 2023: Where to go for colorful peak season