Climate Change and Michigan's Cherries
Michigan’s cherries are a signature example of the effects of climate change on vulnerable agriculture.
Randomly ask people in Michigan what fruit best represents the state, and you’ll commonly here them happily reply, “Cherries!”
The combination of the moderating effects of the Great Lakes on temperatures, rolling hills, and suitable soils creates a welcoming climate and favorable growing conditions for cherries. More than 75% of the country’s tart cherry crop comes from relatively small areas of Michigan, primarily in the Northwestern Lower Peninsula, near Traverse City. It’s a fruit undeniably worthy of being the state’s signature agricultural commodity.
Traverse City is a small, rapidly growing town in the heart of what many call Michigan’s creative crescent, an area that stretches from roughly Mackinaw City to Frankfort along Lake Michigan and features several charming towns that cater to local artists. The community has invested significant effort in reconnecting its tourism economy to some nearby, world-class natural features, like the Sleeping Bear Dunes, the Boardman River, and Lake Michigan. Taken all at once, it blends the feel of a getaway vacation town with a cultural hub. New shops and old shops line delightful streets. Near meal times, the luring smells of baked goods, coffee, and seafood are everywhere as tourists stroll through town wearing swimsuits, hiking gear, or date night attire.
The National Cherry Festival takes place in Traverse City. It’s an annual fixture in the Great Lakes region. The event spans a week and two weekends, drawing in tens of thousands of visitors. There are cherry pit spitting competitions, cherry pie eating contests, wine tasting and every sort of cherry themed delicacy you can imagine. The event crowns the National Cherry Queen and features an air show that often draws military fighter jet demonstration teams like the famed U.S. Air Force Thunderbirds and U.S. Navy Blue Angels. It is a delightfully over-the-top affair.
One quirk of the event is that Michigan’s cherry growing season isn’t conveniently timed with peak tourism season, and most of the cherries used in the various events are either imported or processed from previous years’ harvests. No matter. For those enjoying the attractions, people understand what it’s about and why, regardless of exactly where the cherries came from in their slice of pie. It’s the sort of quintessential festival that every Michigan resident should experience at least once. And for people living in the Grand Traverse area that have to deal with the sudden surge of traffic, it’s a great weekend to get out of town and explore remote places even farther “Up North.”
In late 2011, a coalition of local environmental groups in Traverse City asked me to give a presentation about climate change and potential effects on Michigan agriculture. As a perk, I was invited to a dinner hosted by the organizers of the Cherry Festival. In addition to giving me the opportunity to sample some of the most delicious cherry-themed desserts I have ever had, it gave me the chance to talk to many cherry growers.
At the time, I was hesitant to lead with the fact that I was a climatologist. Climate denial and skepticism, I assumed, would be common in a relatively conservative part of Michigan. Traverse City is a liberal bastion, but the outlying areas are rural and lean libertarian. Over dinner, pie and cherry wine, I did indeed speak to many devoted conservatives and libertarians, but every cherry grower I talked to, regardless of politics, wanted to know more about climate change. They had seen the effects. They had noticed, in their professional vigilance and connection to their farms, subtle, slow changes in the timing of weather events and the phenology of their crops.
In fact, many were frustrated that people in their circles weren’t talking about climate change enough, that it had become political, and folks in their social and political circles were arguing about calling it climate change or weather. Few cared what was causing climate change. They cared about what to do about it.
One gentleman lamented that “scientists use too many big words,” and explained that many in his sector felt ignored by elected officials and university researchers. Others worried about insurance costs, noting that climate conditions were getting less predictable for cherry growing. Some were considering getting out of the business altogether or transitioning to wine grape growing, a decisions that carried high investment costs. A few, penned in by financial constraints, said they had no choice but to keep growing cherries.
At that time, several programs at Michigan State University were, indeed, working with a small subset of cherry growers to understand how climate data might be made useful to them, but the programs were limited by funding, staffing, and time. The program leaders wanted to connect with more cherry growers, but simply didn’t have the capacity. Still, the data collected by those research efforts ended up being prophetic.
The 2012 Tart Cherry Loss
In March of 2012, Michigan experienced a bizarre early spring heat wave. Temperatures reached the upper 80s (°F) in downtown Ann Arbor and were fourteen degrees Fahrenheit above average statewide. Students were sunbathing everywhere on college campuses. Everyone enjoyed the reprieve from the usual gray and gloomy March conditions we often see in Michigan.
While many of us were sitting comfortably in shorts and tee shirts, Jeff Andresen, the state climatologist based at Michigan State University, was worried. In a team meeting connected via conference call, he warned us all that what we were experiencing could be catastrophic if temperatures returned to cooler, near-normal conditions later in the spring. While looking at historical trends in weather patterns and cherry phenology, he speculated and described exactly what ended up happening.
Cherry trees go dormant throughout the winter until warmer weather wakes them up. With increasing frequency in recent decades, relatively warm spring conditions had caused cherry buds to reach a vulnerable period in their seasonal development earlier than has been typical in cooler conditions of the past. The vulnerable threshold is referred to as date of side green. After buds reach the date of side green, they are more likely to be damaged if hit with freezing conditions.
Under climate change, spring temperatures are warming and the date of side green is shifting earlier, but the date of side green is shifting faster than the freezing season is retreating. Even though the growing season is getting longer and spring temperatures are warming, cherry trees are getting exposed to freezing conditions more often at a vulnerable stage of growth. If the date of side green occurs before about April 15th, cherry crops are at higher risk of damage. For years, the date of side green had been occurring closer and closer, on average, to April 15th.
In 2012, the date of side green for much of the Traverse City area was March 19th or earlier. In combination with other weather factors, plants greened up and flowered four to six weeks earlier than normal.
The weather pattern was not isolated to Northwest Lower Michigan. temperature records throughout the Great Lakes region were up to 14°F above average. Much of Michigan’s Upper Peninsula went from having over 40 inches of accumulated snow to bare ground in a single week. Much of Wisconsin experienced a record-breaking length of record-breaking daily high and low temperatures.
April 2012 saw Northwest Lower Michigan return to relatively normal temperatures and periodic freezing conditions. Many well-equipped growers took steps to shield their crops or prepare for the worst. Some sprayed a mist of water on the trees, hoping the mist would create a thin layer of ice to keep temperatures on the buds at freezing but no colder. Others tried using wind fans to keep warm air circulating around the trees. But it was futile. Temperatures fell below freezing and stayed there in an otherwise unremarkable cold snap, then warmed, thawed, and froze again fifteen to twenty times following the unprecedented heat wave. The results were catastrophic to fruit agriculture across the state.
Later on, when we were able to evaluate the weather observations and compare them to historical records, we learned that the 2012 March heat wave in Michigan was a six sigma departure from climatologically normal conditions. That is to say, the heat wave was six standard deviations removed from average. The chance of randomly encountering a six sigma event is about twice in one billion. For comparison, the odds of winning the Powerball lottery are usually around one in 300 million. Of course, we know the chance of such an extreme event is not random. Climate change has made the climatological conditions for such an agricultural disaster far more likely.
In the final economic assessment, Michigan cherry crops suffered a 92% loss. Areas around Traverse City commonly suffered total losses or losses over 95%, the worst year for cherry production in Michigan’s history. Apples, peaches, strawberries, pears, and plums were among other fruits hit hard. For apples, it was the worst year since 1945, possibly ever. Directly attributable losses across the state were estimated at more than $210 million, with crop losses valued at more than $500 million. Other states and provinces, like Wisconsin, Ontario, and New York suffered significant losses from the same weather event.
Some of the associated economic impacts were immediate. In an interview with PBS, cherry grower Pat McGuire said, “We have no crop. We’ve had to lay people off. We’ve had to work extra hours. We did everything we could in the spring to minimize the effects of the freezes that we did have. We felt like we just lost a fight.” Other economic impacts lingered into following seasons, as supply chains shifted to other growers and had to shift back. Processors were forced to temporarily shut down operations while they imported cherries from as far away as Poland. For farm owners, the implications of a severe loss in a season effectively means not being able to collect a paycheck for more than a year, with no guarantee that the next year will be better. It has a chilling effect on the industry, and by extension, the regional economy.
In 2012, tart cherries were also ineligible for any type of crop insurance, meaning growers were truly on their own even if they made every responsible financial decision they could. After the disaster of 2012, the lack of coverage options was somewhat corrected and insurance is now available to many growers, but even the best insurance has limits and can’t reverse climate-driven economic trends that are making certain crop types less reliable.
There were other, less tangible economic effects. While a colleague of mine was holiday gift shopping after the cherry fiasco of 2012, he overheard a pair of shoppers looking at boutique Michigan-branded cherry products in a Cherry Republic store.
“Not this year,” one of the shoppers bitterly exclaimed. “The jam isn’t as good this year and I’ll tell you it’s because of those damned Polish cherries.”
2012 is burned into the memory of growers, climatologists and agronomists, but there have been several challenging years since. Variable weather saw 2015 cherry crops produce one third less cherries than expected. In 2020 and 2021, northern Michigan growers had smaller than average harvests due to early spring warming and a large number of freeze-thaw cycles, conditions consistent with climate change that are expected to become more frequent as global temperatures continue to rise.
Many growers that have the benefit of diversified farms have started openly considering abandoning tart cherries. Some cite climate change as a contributing factor. Many have started referring to their tart cherry orchards as “nuisances,” pointing out that the land would be more profitable if it were repurposed for a variety of other crops.
Gary Bardenhagen, a cherry grower in Leelanau County, lost all of his crop in 2012 and more than half in 2015. He’s seen the increasing vulnerability first hand and says growing cherries is becoming a harder, riskier endeavor.
“I believe climate change is having an impact on our weather,” Bardenhagen told the Michigan Climate Action Network. “It’s becoming more common to have a warm spell in February or early March which melts all the snow and stimulates the trees to move out of dormancy prematurely. The early starts to spring however, do not preclude a late frost event, which can cause damage to the crop.”
Back in 2013, Julie Winkler, a professor at Michigan State presented her team’s recent climate and agricultural research to a large audience of cherry growers. After her talk, one cherry grower stood up and asked, to a round of nervous laughter, “How long should I wait before buying land in the Upper Peninsula?”
The subtext was that as climate conditions became generally warmer, locations farther north might become more preferable for growing cherry crops compared to their historically suitable regions.
After the chuckling subsided, the cherry grower added, “I’m only half joking.”
Addressing the challenge will be complicated and expensive. Researchers at the Michigan State University Horticultural Center and elsewhere have been looking into solutions for almost two decades. Some options include getting growers to switch over to other varieties of cherries that bloom later and are less susceptible to frost. Some cherry growers are trying to breed hybrid varieties that are more resilient to unpredictable weather. Hopeful progress has been made, but as the climate continues to change, so will the nature of the problems growers and researchers need to solve.
Michigan’s cherries are a visible, signature example of the effects of climate change on agriculture. It would be a heartbreaking shame for cherries to become largely untenable in their traditional growing locations, but without significant effort to reduce global carbon emissions and adapt to the effects on a regional scale, it’s entirely possible Michigan may eventually lose much of its cherry-growing ability.