PEDEE, Ore. — A small herd of dairy heifers grazed in the distance as Jon Bansen ambled toward a row of tree saplings bisecting the grassy pasture next to his home in the tiny Willamette Valley outpost of Pedee, Ore.

Bansen planted these trees — a mix of bigleaf maples and poplars — in January to provide shade for cows after a brutal summer in which temperatures rose as high as 116 degrees.

“Last year was the toughest year we’d ever been through,” said Bansen, who runs Double J Jerseys, an organic dairy and family farm in rural Polk County. “That was the toughest summer by a mile, it was so hot and dry.”

Double J Jerseys produces exclusively grass milk for Organic Valley, the country’s largest farmer-owned organic co-op. Grass milk means the cows eat only grass, and no grain.

It also means the cows spend their days grazing in open pastures, rather than being kept in barns. That poses its own set of challenges, including keeping the animals comfortable in the elements, Bansen said.

He described the past two years as seemingly one plague after another. First came the Labor Day wildfires in 2020, which sent up smoke so thick it blotted out the sun for 10 days and affected the cows’ health in strange ways.

“We saw it in hoof health,” Bansen said. “We had a lot more lameness issues, and so did every other dairy that was in the path of that smoke.”

An exceptionally dry spring in 2021 not only stifled forage production, but prompted the vole population to explode, causing more damage than usual, Bansen said.

That led to the summer “heat dome” from late June to mid-July that sent temperatures soaring across the Pacific Northwest. The combination of less grass and distressing heat took its toll on the bottom line, Bansen said.

“With more heat, the cows are less comfortable,” he said. “They’re spending a lot of energy trying to keep cool, instead of making milk.”

Planting trees was one way Bansen said he could address the situation, while providing additional benefits to the land.

Bansen has already planted eight rows totaling more than 1,000 trees in his dairy pastures, with three more rows still to go. Each row runs north-to-south, casting diffuse shade throughout the day as the sun rises in the east and sets in the west — similar to a sundial.

In addition to bigleaf maples and poplars, Bansen said they are trying several other species including white oak and quaking aspen. A few rows have been interspersed with thick shrubs such as red osier dogwood and snowberry, attracting wildlife and pollinators.

Once they are big enough, Bansen said shade from the trees will provide much-needed relief for both cows and grass on hot days.

“The job for our cows, because we’re a grazing dairy, is out here. It’s not in a barn,” he said. “I need to be able to keep them out on the pastures as long as possible through the days, and that includes the hot, sunny days.”

Beyond providing shade, Bansen said the trees will sequester carbon and replenish organic matter in soil as leaves fall to the ground. They also improve wildlife diversity on the farm, including natural predators of voles that can keep the rodent’s population in check.

Though it will take years for the newer seedlings to reach maturity, Bansen said it is a long-term investment in the health of his operation.

“Cows and trees just go really well together,” he said. “Plus, consumers love trees. There’s no doubt about it.”