Pawpaw, North America's native fruit, badly affected by climate change

Stubborn drought in the U.S. state of Ohio and the shifting weather patterns influenced by climate change appear to be affecting North America's largest native fruit: the pawpaw.

Avocado-sized with a taste sometimes described as a cross between a mango and banana, the pawpaw is beloved by many but rarely seen in grocery stores in the U.S. due to its short shelf life. The fruit grows in various places in the eastern half of North America, from Ontario to Florida. But in parts of Ohio, which hosts an annual festival dedicated to the fruit, and Kentucky, some growers this year are reporting earlier-than-normal harvests and bitter-tasting fruit, a possible effect of the extreme weather from the spring freezes to drought that has hit the region.

Take Valerie Libbey's orchard in Washington Court House, about an hour's drive from Columbus. Libbey grows 100 pawpaw trees and said she was surprised to see the fruit dropping from trees in the first week of August instead of mid-September.

"I had walked into the orchard to do my regular irrigation and the smell of the fruit just hit me," said Libbey, who added that this year's harvest period was much shorter than in previous years and the fruits themselves were smaller and more bitter.

While Libbey attributes the change to heat-stress, it's not clear if drought alone – which is gripping parts of Ohio and Kentucky for the third year in a row – or increasingly extreme, unpredictable weather are affecting the fruit.

"Pawpaw growers are finding we just have to be prepared for more extreme weather events. Last year we were hit with late spring freezes that killed off a lot of the blossoms in the spring time period. This year we were hit by the drought," Libbey said.

That's in line with the effects human-caused climate change is having on the Midwest according to the National Climate Change Assessment, a government report that comes out every four or five years. Last year's report said that both extreme drought and flooding were threatening crops and animal production in the region.

"We're definitely seeing kind of a change in our weather patterns here," said Kirk Pomper, a professor of horticulture at Kentucky State University. He added that the easiest way to observe the effect of changing weather patterns on pawpaws is when the trees flower, which tends to happen earlier now than before.

Chris Chmiel, who owns and operates a small farm in Albany, Ohio, about 90 minutes southeast of Columbus, said he used to have several hundred pawpaw trees but is down to about 100 this year thanks to erratic weather patterns, including extremely wet weather some years followed by severe drought.

Chmiel said that pawpaw trees, which are generally considered low-maintenance, don't like to have their roots submerged in water for too long, which his trees experienced in 2018 and 2019 during particularly wet spring conditions.

Since then, Chmiel saw a large decline in his trees, especially the older ones, which produce ethanol when stressed and attracted an invasive beetle that was damaging to the tree.

"For years, we had great crops year after year," said Chmiel, who described the invasive beetles as the biggest recent challenge. But, he added, some of his pawpaw trees come from the wild where the plants were exposed to several microclimates and habitats.

The pawpaw was domesticated by Native American tribes, and has supplemented many communities' diets since then.

Because pawpaw trees are native to the region, they have long been considered hardy. Chmiel is hoping that will help his remaining trees survive unpredictable weather and invasive species.

"I feel like that is a resilient system," Chmiel said.