Drought is dulling fall foliage, but there are still vibrant pockets

Pumpkin spice season has arrived and with it shorter days, cooler nights and the unshakable feeling that winter is coming. But some people wait all year for fall, rejoicing in the splendor that is autumn foliage. Before leaves are shed, each turns a shade of rusty brown, amber, vibrant yellow, maroon or a fiery red.

However, this year’s fall flock may be duller than usual in many places because of an exceptionally hot and dry summer, which put the trees under stress. Massachusetts, one of the most popular places for leaf peeping in New England, was in a severe drought for much of the summer and is feeling the effects. Portions of the Midwest and the West were – and still are – experiencing severe to exceptional drought.

“In general, moderate heat and drought can move leaf senescence (leaf drying up and dropping),” Andy Finton, a conservation ecologist at the Nature Conservancy in Massachusetts, wrote in an email. He said the fall colors are likely to feature more yellows and browns in these drought-stricken areas.

Even so, he said, people can still find pockets of vibrant color, especially in wetter low areas and wetlands.

Here we break down what causes the changing colors, where the foliage stands now and how you can enjoy the colors.

Why do leaves change color?

Leaves are like mini solar panels for a plant. Their job is to absorb sunlight and produce food, or glucose, through photosynthesis. That requires storing the energy contained in sunlight. Chlorophyll is a pigment that absorbs blue and red wavelengths of light but does not take in green light. Instead, it bounces green light away, which is why we see chlorophyll as green.

During the autumn, the days grow shorter. That translates to less sunshine for plants, and leaves stop producing food. The chlorophyll breaks down, revealing different colors underneath.

Some of those other colors are enhanced in the fall through other chemical reactions. Red anthocyanin pigments can be boosted by near-freezing temperatures, although readings below 32 degrees induce an early frost, which weakens colors. Rain and overcast skies also can mute the colors of fall foliage.

“For best fall color, temperature and the amount of moisture are the main influences coupled with the duration and angle of sunlight,” Kyle Cotner, creator of theFoliageReport.com, wrote in an email. “For the best color to be displayed, an area needs cool nights (yet not freezing) with sun-filled warm days.”

When the leaves start taking too much energy from the tree, the leaf-shedding process begins. The loss of leaves helps the trees retain water during winter and use less energy to stay alive.

Severe drought in many areas in the country accelerated the leaf dropping this year, said Finton. The stressed trees no longer could maintain their leaves, so they start shedding sooner.

“This means they turn brown, before they have a chance to break down their green colors to expose yellows and oranges underneath, and before they have a chance to develop brilliant red colors for species like red maple and sumac,” Finton wrote.

In areas not affected by severe drought, however, he said recent rainfall and cool conditions have allowed some trees to hold their leaves long enough to show more reds.

Where are the leaves changing color?

Trees at higher elevations generally peak first, since they respond first to the dwindling daylight hours, which help trigger the color change.

In New England, only the extreme northern tip of New Hampshire is at peak color, earlier than last year. Cotner’s roundup notes that “high color” can be found in parts of the Green Mountains in Vermont as well as in northern Aroostook County, Maine.

Finton and Cotner said a recent drop in temperatures probably brought on faster change in these states, which were not much affected by drought this summer.

“Recent cold weather played a large role in fall colors within the Northeast and parts of the Mid-Atlantic region,” Cotner wrote. “Compared to last year, we at The Foliage Report notice leaves moving much quicker to peak fall color due to the colder weather.”

Finton said peak fall color has yet to arrive in Massachusetts, where the color change starts in the higher elevations in the western part of the state, then moves toward Boston and the coast. However, a severe drought in the region has impaired leaf color.

“In eastern Massachusetts, we’re seeing less fall color and some earlier color,” Finton wrote. “Some trees have leaves that have withered before having a chance to turn color.”

Most areas in the eastern United States north of the Mason-Dixon Line away from the coast are in the “low color” category, according to Cotner’s roundup, as are areas in the Appalachians across the interior Mid-Atlantic. Forecasts show much of the lower elevations in the Mid-Atlantic will peak around the week of Oct. 24 while some of the highest peaks (above 3,000 feet) in northern West Virginia are near peak.

Not much color is reported across the Southeast and Desert Southwest, but forecasts indicate the regions may peak at the end of October to the beginning of November.

In the West, low to moderate color is prevalent in the Columbia River Basin as well as in the mountainous terrain of Wyoming and the Rockies. High to peak color can be found at some of the mountain tops. Splashes of color are also showing up in California’s Sierra Nevada. Forecasts show color increasing through October, first in the mountains and last in the valleys.

The Upper Midwest, northern Great Lakes, Corn Belt and parts of the Ozarks are seeing low to moderate color, but their foliage will progress rapidly in the next couple of weeks. Northern Minnesota is in the “high color” category and about a week or so away from peak.

No matter where you live, Cotner says, there is some place for a hint of color – although seeing it may require a bit of driving.

“Every U.S. state except for Hawaii (the hardiness zone is too high, stays green all year) has fall foliage,” he wrote. “From the tundra in north Alaska (peaks in August) to the cypress trees in the swamps of central Florida (peak in December) there is fall color to be found.”