The birds and bugs are singing at Dave Bohnhoff’s farm in Plymouth, Wisconsin. His hazelnut orchard is a paradise for chipmunks, blue jays, and insects, as well as a group of visiting farmers here to learn about growing the nutritious crop themselves.
A University of Wisconsin-Madison professor emeritus of biological systems engineering, Bohnhoff guides them through a field where many hazelnut varieties are growing, each one labeled with a stake.
“The whole reason for that is to find out what grows here and what doesn’t,” he says. “When will this stuff get wiped out? When won’t it?”
Bohnhoff is hosting the group as part of a weeklong series of events across the state held by the Upper Midwest Hazelnut Development Initiative, a group of researchers and emerging crop specialists dedicated to bringing the hazelnut industry to light. Besides testing which hazelnuts thrive here, his passion project is developing a combine that can harvest and de-husk nuts simultaneously — in the hopes that future growers could use such a device to ease harvesting.
Many hazelnut-curious farmers in the region are drawn to the novelty of a native nut. Farmland in the Upper Midwest is mostly used for corn and soybeans. And most hazelnuts are grown overseas, in Turkey.
The practice of planting long-lived, woody shrubs or trees alongside annual crops is known as agroforestry. Here, hazelnuts could return parts of the landscape to something resembling the oak savannas that once blanketed Wisconsin before settlers cleared the land for farming.
Perennial crops — like hazelnuts — don’t need to be re-planted year after year, which comes with many environmental benefits. They suck up agricultural pollution, improve water quality, and lock up planet-warming carbon. And they hold onto soil that otherwise quickly erodes from farmland.
“Any of these perennial crops are going to be better for the environment because you’re not doing this continuous stirring of the soil and breaking down all those microbes,” says Ann Kowenstrot, an emerging crops specialist with UW-Madison extension. “Any perennial crop that we can get people to grow — and show that they can be successful — is going to better in the long run.”
That’s just what interested Tom Griep, who planted hazelnuts two decades ago at his farm in Dubuque, Iowa.
“Where I live in the Driftless Area, we have terrible problems with soil erosion, and every time we turn the soil over, a lot of it washes away,” he says. “I have the good fortune to own some land. So I thought I’d look into planting different things.”
Now he hardly sees any runoff. And he loves hazelnut pesto.
The Upper Midwest hazelnut research hub formed in 2007 to support the new industry. Jason Fischbach, a woody crops specialist with UW-Madison extension, was charged with diversifying economic options in rural counties where dairy farms had collapsed.
“We needed to find other options for farmers and for the ag economy,” says Fischbach, who co-leads the Upper Midwest hazelnuts initiative. “Started looking around and turns out that there’s this plant that grows wild all over Bayfield County: American hazelnut.”
The plant breeders hunted for the best American hazelnut plants in the region — ones with lots of big nuts, well-suited for commercial production.
In the years since the work began, they’ve identified the prize cultivars. Now, the challenge is propagation. The plants haven’t been taking to typical nursery methods; because the American hazelnut is adapted to drought-prone, sandy soils, it’s been going dormant when it’s stressed.
“If we can’t get copies of these good plants out to growers, we’ve got nothing,” Fischbach says. “To give you some perspective, our goal is 20,000 acres by 2030. That’s going to require 9 million plants. Right now, we’re producing maybe 1,500 to 2,000 a year.”
These days, he spends most of his time in the nursery trying to figure it out. He says he remembers what it’s all for on crisp autumn mornings when the hazels are ready for harvest.
“You get out there in the field, and you see the potential of these top plants,” he says. “You see these plants just loaded with hazelnuts. Then you get them cracked and roasted, and you’re eating them, and it’s like, ‘Whoa, this is so worth pursuing.’”
In the last 20 years, farmers that first experimented with the nascent crop have aged out. Many early adopters have been older or retired. Fischbach says it’s essential to have younger folks take on the mantle, like Bobbi Jo Merten, who is attending the field event at Dave Bohnhoff’s farm.
“I’m interested in things that we can grow in marginal land on my family’s old dairy farm that’s now just conventional agriculture,” says Merten, who is from St. Cloud, Wisconsin.
“I moved off the family dairy farm, went to school for a long time, got a real job, and I’m 13 years into that career journey,” she says. “I’m looking forward to seeing what that career stage looks like. But I’m also interested in how I can plant seeds literally now.”
It’s overwhelming when she thinks about the labor and money it takes to run an operation like Bohnhoff’s. But in this hub of hazelnut growers, there’s a community that’s always willing to share what they’ve learned.
