From drought to severe storms, climate change is a challenge for Maine’s iconic wild blueberries – The Boston Globe

The bountiful harvest — a boon for Wyman’s and the other 484 wild blueberry growers in the region — was a month early this summer.

Growers were ready for it, though, staying laser-focused on changing climate patterns and extreme weather events for the past several years. Cultivators of the wild blueberry, a species only commercially farmed in Maine and eastern Canada, have transformed their growing practices to deal with more heat and swings in precipitation, conducting research on their fields in real time and adjusting timing, fertilizer, and irrigation year after year.

“The crop adapted to the climate in a certain way [over time], but now we’re seeing this rapid change,” Tooley said. “We’ve had to become more flexible and more adaptive in how we manage this crop, and respond to climate change to help the plant thrive.”

Nearby in the field, hand pickers in long pants and wide-brimmed hats swung metal rakes low to the ground, pulling up the fresh berries from patches that sprouted about ankle-high. Meanwhile in the neighboring town of Cherryfield, widely considered the wild blueberry capital of the world, other Wyman’s farmers steered tractor-sized mechanical pickers back and forth across the fields, yanking up blueberry shrubs and catapulting the berries onto a conveyor belt that shuttled them into crates.

The wild blueberry industry contributes over $360 million to Maine’s economy each year, according to the Wild Blueberry Commission of Maine. Wyman’s alone, one of the state’s larger operations, employs roughly 300 people year around; employment numbers vary for the other approximately 500 growers.

Unlike the high-bush blueberries found in supermarkets across America, wild (or low-bush) blueberries are not planted; rather they spread on their own through underground roots that farmers carefully manage to encourage their growth.

A resilient plant that can grow everywhere from mountaintops and rocky cliffs to sandier coastline soil, wild blueberries don’t need tilling, and typically don’t require much care at all beyond biennial pruning and swarms of honeybees trucked in to help the plants bear fruit. (Wild blueberries are biennials, meaning the plants produce fruit every other year.) Even during difficult years marked by frost or drought, Tooley said, the plants self-regulate to some extent, with “better pollinator efficacy in fields with more damage.”

Even so, research indicates that the region’s blueberry barrens, places where the fruit naturally grows, are warming faster than the rest of the state. And as the climate becomes not just hotter, but more unpredictable, growers like Wyman’s are increasingly investing resources into predicting future weather conditions, and tending to plants with ever more attention to ensure the fruit makes it to harvest.

“Climate adaptation and mitigation planning … is the challenge of our time. If we want to have a functioning and healthy agricultural system in this country and around the world, we have to be thinking about this,” said Rachel Schattman, a former vegetable farmer and sustainable agriculture professor at the University of Maine, who is working with Wyman’s to model the impact of weather patterns on wild blueberry production.

“If you apply climate change to a market setting … it’s becoming more and more something that farmers think about a lot, and they understand it affects their business a tremendous amount,” she added. “People used to say, ‘My grandfather always started harvest on the first week of August.’ No questions asked, that’s just when the harvest starts. But that’s not reliable anymore.”

Tooley said the shift away from the “calendar method” is industrywide; instead, she and other farmers and ecologists are in the fields multiple times a week throughout the spring, even tagging specific plants to closely study them for signs of buds preparing to flower, and flowers preparing to bear fruit. This year, the harvest in Downeast Maine started in early July and is expected to wrap up weeks before its usual end in mid-September.

While summer weather has varied sharply in recent years — with 2020 and 2022 marked by drought, then a deluge of rain last year — Tooley pointed to three major trends in berry growth that farmers have noticed in the past decade: a longer, earlier growing season, warmer temperatures, and more precipitation. And though that may sound like good news for the harvest, those conditions can harm the blueberry plants, which respond in real time to changing weather patterns.

For example, Tooley said she’s repeatedly observed what ecologists are calling “fall bloom” during unseasonably warm autumns, when the shrubs mistake the heat for springtime weather and begin to flower six months early. Those buds are then damaged during winter frost, reducing the amount of fruit the plant is able to produce the following year. Similarly, “snowpack,” or a layer of compressed snow over the ground, historically protected the low-growing plant from harsh winds and severe cold temperatures. But with less snowfall in recent years, the plants are forced to face the winter elements.

Growers are limited in what they can do to protect the vast acres of land during the colder months, but once spring hits, Tooley said, her team kicks into high gear to try and simulate “normal” growing conditions as much as possible.

“We’re definitely bringing in bees earlier than we used to … and irrigating more,” she explained. “The plant is doing everything it can to ripen and reproduce, and we have to give it everything it needs to keep going.”

Each year holds lessons for the next one. After the first year of intense drought, for example, growers introduced a nitrogen-based fertilizer to the help the soil retain moisture on hotter days. And because of last year’s heavy rainfall, when many of the berries were soggy from overwatering, Tooley said that this year the team is careful to pull back on irrigation on rainy days and adjust the frequency of watering to be more often on sunny ones.

Of course, it all leads up to the first day of harvest, which kicks off a period of nonstop berry collection. And if they get it right, berries abound — so many that harvesters don’t need to worry about crushing a few shrubs in the process.

“We work all year — for two whole years — to make this happen, then we have four weeks to get it out of the ground,” Tooley said. “A lot of people’s livelihoods rely on this, and while we trust the resiliency of the crop, we also want to give it the resources to help it flourish and continue to sustain the people that depend on it.”

Ivy Scott can be reached at ivy.scott@globe.com. Follow her @itsivyscott.