Jonas Frei

Frei knows that sense of discovery first hand. While walking through a botanical garden in Zurich, something on the ground caught his eye. “I could immediately see it was a walnut, but it was unlike any walnut I’d ever seen before,” he recalls. It turned out to be a butternut, a North American species of walnut. “That was the moment I realised: there aren’t just the walnuts we all eat. There are many more species.”

He began researching the walnut family, eventually writing a book, The Walnut, about its history and diversity. “Cultivated plants are not simply species that exist independently from us: they are the result of long relationships between people and plants”, Frei explains. “Generations of selection, cultivation and adaptation have produced the varieties we eat today.” 

“In the case of the walnut, for example, varieties like Franquette and Lara dominate supermarket shelves, while countless others remain invisible to consumers. Some are astringent, others are sweeter. The butternut I first encountered in Zurich has an almost buttery flavour, but it doesn’t crack as easily – which is the reason we rarely encounter it in shops.”

The walnut is just one example of a much wider narrowing of the plants we eat. As the globalised food system concentrates production around a relatively small number of varieties, others disappear from fields, shops and, eventually, from our diets. What is lost with them, Frei argues, is not only a range of flavours, but also genetic traits that could help agriculture adapt to an increasingly unpredictable climate. 

“The consequences of this narrowing are perhaps clearest in almonds, the subject of my latest book,” Frei says. “Modern production has increasingly concentrated around a small number of highly productive cultivars. Under intensive growing systems, with large amounts of water and other inputs, they can produce yields that traditional almond trees simply cannot match. That is why, across the Mediterranean, ancient and traditional almond groves are shrinking or disappearing.”

Frei believes seeds could be part of the way back. “Each seed carries genetic traits, but also the imprint of generations of selection: choices made by farmers and communities about what tastes good, what survived in a certain landscape, what ripened at the right moment or worked within a particular cuisine. It’s a capsule of life, a point where past and future meet. Losing that means losing genetic material, flavours, knowledge and cultural history.” 

Luckily, Frei sees a growing number of farmers diversifying what they grow, returning to local varieties and reconnecting production with regional markets. Climate change is part of the reason, he says, but there is an economic dimension too. “It’s a way for farmers to become less dependent on the globalised market, and thereby retain a fairer share of the income from the work they do.”

“A lot of what I do – with my books, photographs, artwork and even social media posts – is to show diversity that is, or could be, part of everyday life, but is often overlooked,” Frei says. That diversity extends far beyond food. “Much of it is close enough to touch. You can just open your eyes, wherever you are, and see how much plant diversity there is, even in cities.”

His book Urban Wild Plants grew from that idea, documenting the ecological richness found along pavements and walls, on roadsides and in patches of disturbed ground. After it was published, Frei began receiving messages from readers who had started paying closer attention to their own surroundings. “People wrote to me saying: ‘I’m looking differently at the wild plants in my region. I’ve discovered so many species outside my garden, or on the street I walk down every day on my way to work.’”

That response gets close to what Frei hopes his work can achieve. He is acutely aware of the biodiversity crisis unfolding around him, but chooses not to make warning the starting point. “I could have posted political statements with every botanical photo I’ve ever shared,” he says. “Instead, I might post an image of different varieties of corn, accompanied by a scientific description. It gives everyone the possibility to admire it. And hopefully, in the longer term, it connects people who aren’t already in this bubble with the idea of diversity being a positive thing.”

Ready to support a localized and diverse food system? Read our interview with Local Futures founder Helena Norberg-Hodge.