Two city dwellers’ deep winter greenhouse supplies Minneapolis co-ops with sustainably-produced microgreens throughout the frigid months.
Story by Amber Newman, photos by Jill Thiel
Three little sprigs of red-veined sorrel might daintily top a dish at a fine-dining restaurant, but that’s probably all you’re going to see of them. Microgreens, which are harvested soon after they sprout and make their first few leaves, are condensed vessels of flavor and nutrients often used in salads, sandwiches, and as garnishes. They can be the tiny beginnings of any edible plant—lettuces, vegetables, herbs, and some flowers. Because microgreens have a short shelf life, and specialty plant varieties like red-veined sorrel are costly to grow, it’s rare to indulge in them.
Jill and David Thiel are changing this. They are the proud microgreen growers and owners of Minneapolis’ first deep winter greenhouse. The Thiels have been growing edibles in lieu of a sprawling green lawn for the past ten years, but when they learned of an opportunity to have year-round produce, they decided it was time for an addition.
“With a deep winter greenhouse, you’re able to leverage solar resources. In a warehouse, you have to have lights and it comes to be less economical,” says David. The 10-by-18-foot space has redundant heating systems: an air source mini-split heating pump (energy efficient heater for small spaces) and warmth from the exhaust line of a rocket mass heater (modern wood-burning stove). David says the greenhouse is designed to trap in the heat and is very efficient.
Despite Minnesota’s frigid negative double digit winter temperatures, the greenhouse stays above 50 degrees with minimal energy use. According to David, a large contributor to having to supplement heat is that a neighbor has a giant pine tree blocking much of the light. “If you’re relying on income from the crops, you want to have a backup. This last winter was extremely cloudy, and you can’t make it that way,” he says. “It probably won’t go below freezing, but you’d really want to make sure.”
It took one year to build the deep winter greenhouse, and they opened it to the public in December 2015. Soon after, the University of Minnesota caught wind of the project and wanted to know how they got a building permit. David says he referenced the university’s website to design the greenhouse using 3D software before taking the plans to the city for approval.
Shortly after opening in December 2015, the couple established retail hours so people could tour the greenhouse and indulge in tastings. “The cool thing about people coming in is that we can cut [fancy microgreens] fresh and they can see the plants and colors,” Jill says. “It’s also a really great atmosphere: people coming into 70 degrees being surrounded by plants when it’s 20 below [outside].”
To launch their business, the couple tried every avenue of sales and even secured a ten-person CSA, or community supported agriculture. Though everyone was happy, the grocery outlet was the most successful. “We had a lot of people coming through that say they want to do something like this. And they come back and bring their friends. The word of mouth is working,” Jill says.
Originally, they contacted Seward Co-Op hoping to sell baby basil, but the produce buyer asked them for microgreens. Out of the twenty types they were growing, they curated a flavorful mix called Hiawatha, including cabbage, broccoli, sunflower, radish, and cilantro.
In February 2016, The Sustainable Farming Association kicked off their annual Deep Winter Greenhouse tour at Thiel Gardens, which brought a lot of appreciated attention to their new business.
Jill says they are at half capacity, and the plan is to let the business continue to grow, welcome larger accounts as time goes on, and transition almost entirely away from outside sources of income. But the Thiels’ overarching goal and root of their passion lies in food sustainability and security. “The north can become more independent in where our food comes from,” Jill says. “It surprises me we haven’t been adapting to this longer.”
Curious and hungry plant enthusiasts are welcomed to contact Jill and David Thiel for an educational tour of Minneapolis’s first deep winter greenhouse and are encouraged to stay tuned for future updates at thielgardens.com and facebook.com/thielgardens for touring hours.
Amber's currently based in Minneapolis as a freelance editor, writer, and floral designer. She's worked on over a dozen organic farms in every corner of the country and spent summers in California and Vermont on flower farms, as is her main passion. She also deeply believes when we eat food from local, small farms or independent growers, we take in the positive energy and joy that was put into planting, nurturing and harvesting those crops.
Amber Newman packed up her car and became a vagabond for a year after graduating form Metropolitan State University in Minnesota. She worked on more than a dozen organic farms in every corner of the country. As a perpetual wanderer, she's based in Minneapolis as a freelance editor, writer, and floral designer. She's an advocate for ethical and sustainable equality-based products and organizations. Her mission is to help connect all humans with the pure beauty of the land. Read about her farming adventures on her website With Dirt On My Hands and follow her on Instagram @bambwhat.