For seven winters, Carol Ford and Chuck Waibel have been supplying weekly boxes of fresh cold-weather vegetables and baby greens to a 12-member CSA (Community Supported Agriculture).
Under the name “Garden Goddess,” they grow the food in their self-designed 16×22 low-energy northern greenhouse. Inside that deceptively small space is 3,520 cubic feet, with roughly 150 row feet of prized baby greens rotating in a simple system of hanging planters suspended by rope harnesses.
The couple shared their experiences and their expertise with about 23 people from surrounding states and provinces at a recent workshop here.
“We’ve nailed low-energy winter food production — and are here to help you do so, too!” they told their audience. Their enthusiasm for vegetables and the potential for the winter greenhouse to bring fresh local food to northern people is contagious.
Not a new idea
The idea of the low-energy northern greenhouse is not new. Back in the ’70s, plans were widely available for passive solar south-glazed lean-tos filled with water barrels to hold the heat.
Chuck, whose interests include polymath, systems analysis and speculative fiction, already had a reference library on hand when he and Carol began to design a northern greenhouse that others could easily adapt or replicate.
“You need a mindset almost like building a spacecraft,” Chuck said. “Make it tight. Make it careful.”
And make it easy.
All materials, with the exception of the polycarbonate panels, are readily available at any local building centre. What was missing from those earlier plans was a planting guide. That research is entirely Carol’s contribution.
Now a master gardener, she grew up in a garden-less household in suburban Iowa, where vegetables came in cans. She developed the love while studying creative writing in college.
In 2005, Chuck and Carol were living in Milan and enjoying fresh vegetables from their local CSA. When the season ended in mid-September, they dreaded the return to store-bought vegetables from far away. They started researching ways to extend the season.
“If you find yourself saying somebody really ought to do it, then it ought to be you,” Chuck said.
The couple enrolled in a holistic Land Stewardship course called “Farm Beginnings,” researched cool-weather crops, designed a greenhouse, developed a business plan and shopped for a business loan. They kept everything small in case of failure. Carol recalls a lot of sleepless nights the first two winters.
Ford and Waibel generously share their expertise in the self-published and very readable Northland Winter Greenhouse Manual — a Unique, Low-Tech Solution to Vegetable Production in Cold Climates, produced with assistance from the University of Minnesota West Central Partnership.
When the first edition sold out, the book was tweaked and reprinted with additional support from FARRMS (The Foundation for Agriculture, Rural Resources Management and Sustainability), a North Dakota-based not-for-profit organization that enthusiastically endorses their work.
Growing produce in winter
In the manual, Carol lays out a planting schedule by dividing winter into three seasons: Diminishing season (late September to mid-November), Solstice season (late November to early January) and Expansion season (mid-January to late March), each with its own possibilities and pitfalls, along with a detailed list of plants that work, and when and how to plant them.
Large slow-growing plants such as broccoli and swiss chard go into the ground for a single harvest, although Carol has recently switched to the faster-growing broccoli raab.
Three rotations of pac choi and chinese cabbage are harvested from the floor beds. But the real bonus is the fast-growing and tasty greens, started weekly on heat mats and then moved up into slings where they can be cut in as little as three weeks, and be harvested as many as three times before they are sent outside to compost.
The clients of the Garden Goddess CSA live for these little gourmet baby greens, which include sweet lettuces, peppery brassicas, Asian greens and mustards, and colourful baby beets and collards, plus the more unusual Vitamin Green and Claytonia, or miner’s lettuce.
Yes, we grow no tomatoes
People typically ask whether they grow tomatoes. The answer is a big “no.”
Working beneath the greenhouse is an underground heat sink — an excavation below the frost line filled with loose river rock that is heated by a perforated pipe full of warm air from the black pipe “solar heat collectors” located at the top of the structure.
Chuck calculates that the design uses only one-thirtieth the energy of a standard greenhouse, even with a supplementary heat source that tops up temperatures on those rare nights that follow three consecutive cold and cloudy days when the heat sink begins to cool.
It is impossible to grow fruiting veggies without adding massive amounts of supplemental light and heat to this model.
Winter greens with a low carbon footprint
So tomatoes and cucumbers are out. Instead, winter gardeners can enjoy fresh baby greens and tender, sweet, dark-green vegetables that happily grow through the darkest days of winter in temperatures that can drop to -2 C in the corners at night here in Manitoba.
A method on the move
The interest in low-energy greenhouses and winter crop production is growing. Manitoba Hydro and University of Manitoba have experimented with similar designs.
Chuck and Carol envision even more northern winter greenhouses springing up, bringing fresh food security to schools, hospitals and even whole communities. The mayor of Minneapolis recently toured their facility and promised to look at amending codes to make it easier for urban builders. Closer to home in Milan, they are working to create a distribution hub with a very large greenhouse and off-season vegetable storage for local market gardeners. They are always willing to speak on the subject, and invite interested people to contact them through the Garden Goddess network at gardengoddessnetwork.ning.com.