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“Here we are in mid-November, and we’re just under 10 hours of daylight [a day],” said Fortier, who added that the challenges of growing in winter have always been much more about lack of light than temperature. “We got all our crops in a greenhouse, eight to 10 weeks ago, and now the crops will be staying in the ground, not really growing anymore because there’s not enough light, but just staying in a cool place. We will harvest them every week until the growth picks back up in February.”

For the last few years, Fortier and Catherine Sylvestre, a professional agronomist and director of vegetable production at the Ferme des Quatre Temps or Four Season Farm—one of three farms at the heart of Fortier’s Market Garden Institute—have gotten serious about winter farming. When the pandemic disrupted multiple supply chains and made it challenging to get fresh vegetables from southern climates in Eastern Canada, policymakers in the region started thinking seriously about food sovereignty. As Fortier writes in the introduction to his new book, The Winter Market Gardener: A Successful Grower’s Handbook for Year-Round Harvests:

“In Quebec, one of the main policies was a massive investment program to double the number of greenhouses within five years. . . . Unfortunately, the idea only got picked up by large-scale producers . . . [who] grow summer crops in monoculture regardless of the season.

Catherine and I decided then to propose our alternative: to invest the same amount towards better equipping and educating 50 family farmers, so that they can use greenhouses and extend their growing season to provide a diversity of seasonal and local produce.”

The book, the second for Fortier—who also teaches the Market Gardener Masterclass (from which more than 4,000 students have graduated) and whose institute has also sparked a restaurant, magazine, and reality TV show—expands on the existing literature on winter farming. It takes a research-based, data-backed approach that he hopes will inspire a whole generation of small-scale farmers to consider growing food in winter.

Civil Eats spoke with Fortier about the book, the history of winter farming, and what it might take to get more people to love the taste of winter greens.

Winter farming is often seen as a missing piece of the local food puzzle, because that’s when consumers are especially reliant on produce from places like California, Mexico, and Florida. Why did it feel important to take a data-driven, highly scientific approach to this guidebook to start filling in that gap?

When I was a younger grower, I was really influenced by Eliot Coleman, who pioneered modern winter farming [in the U.S.]. And I had some anecdotal experiences on my farm where I was doing winter farming and trialing it. Then around six years ago at Ferme des Quatre Temps (FQT) Farm, Catherine and I started to do some research trials, where we tested out planting different cultivars at different times of year. And after a few years, we really got the hang of it.

After COVID, there was a big push for more super high-tech greenhouses where they grow tomatoes, peppers, and even strawberries, but no one was talking about lower-tech greenhouses growing greens that are super hardy.

And so the book is about getting the message out there that food sovereignty is about having produce in the winter that is in tune with the seasonality, with the low-light conditions, with the coldness. And these are the crops that we grow. It was also about sharing all the research that we have done at FQT Farm, and sharing it so that other growers can apply some of these principles and have success on their own.

And nutritionally, the greens that you’re growing are very different than tomatoes and cucumbers and strawberries, right?

Yeah, that’s what we’re realizing here. People assume that cold is something that stops us from growing vegetables in the Northeast, but because of the coolness factor, our veggies have very concentrated sugars; their Brix level goes up, and their nutrient density goes up. And when these vegetables get a light frost, they change and become so incredibly flavorful.

Can you describe this idea of “hardening” the vegetables? It sounds almost like you’re able to train the plants to adapt to the cooler temperatures.

When we start to get cool [autumn] nights on the farm, I leave the [row covers] open on the greens beds for two or three weeks, so that they get acclimated slowly to frosty nights. Then when we have colder nights in December and January, these crops will be able to handle it. Some of them can get a hard frost and survive; kale, spinach, and others can get a light frost.

I loved your description of rolling back the cloth and seeing the frozen vegetables, but then watching them come back to life as the day warms up.

Every fall at FQT farm we train 10 apprentices, and we bring them out when there’s a frost, and they’re always super disappointed. They’re like, “Oh, after all our effort putting these tunnels up, the crops are dead.” And then we laugh because the next day, we’re like, “Come on, and check it out.” We take the snow out of the beds and the crops are fine.

How did you arrive at the idea to use greenhouses that are just warm enough to prevent freezing of some crops at night?

We knew from visiting other farms and reading writing by Coleman and other growers that it was possible to grow vegetables in winter. But is it economically viable? That’s really the question we were asking ourselves when we started out. We measured the yield harvested when we planted the crops at different times in the fall—before the 10-hours-of-sunlight cutoff [which is different in different places]. We also measured the cost of the operation, including the energy cost for heating greenhouses and the cost of labor involved in rolling and unrolling the row covers day and night. We did the math on all these different techniques. And what we were trying to find is the sweet spot where we have [ample] yields and an economic upside. We’ve also been experimenting with going carbon neutral with different heating systems with water tubes and electric heat pumps.

We wanted to reinvigorate younger growers and get them excited about the possibility of growing year-round. If they already have markets and infrastructure, we’re saying why not try to make the most out of them and go year-round?

Do you have thoughts about what it might take to get more people to eat the kinds of vegetables you’re growing? We know there’s an appetite for tomatoes, cucumbers, and strawberries. But some consumers are less familiar with Asian greens and bitter greens and other different flavors.

That’s an important element. All the farms can grow year-round, but then they need to have markets. And [there] have been pockets of places where people are so excited about local foods, especially in the Northeast, Maine, Vermont, upstate New York. There are a lot of places where there’s demand and consciousness around the local food systems and the impact of the globalized economy. People are more aware than ever.

But if this is going to go further, there needs to be a collective movement toward food sovereignty. And I believe food sovereignty should be localized at the state or province level. Each state should have a policy of resilience, especially in the face of climate change and future pandemics. We can grow almost everything! So, why would we want to import so much of it from abroad? There’s an environmental cost to that, and there’s a social cost. Our work is nested in a bigger movement, which is about decentralizing the food system and empowering communities with access to super healthy, local foods.

This interview has been edited for length and clarity.