Weatherproof greenhouses offer robust growth conditions
In the heart of Minnesota's southeast, where cold winters and the edge of "Tornado Alley" make farming a challenging endeavour, Owl Bluff Farm stands as a beacon of resilience. Run by Carrie Calvo and a small, dedicated team, this organic vegetable operation in Houston County is making strides in sustainable farming.
Facing long days, cold winters, and unpredictable conditions, the farm's customer base has grown significantly. To combat these challenges, Owl Bluff Farm has turned to a unique solution: farm-scale deep winter greenhouses. These innovative structures, built in partnership with the University of Minnesota and the Regional Sustainable Development Partnerships (RSDP), are designed with resilience in mind. They harness solar power for heating and store energy in thermal mass materials like soil or rock, enabling year-round production and reducing dependency on fossil fuels or external energy sources.
These greenhouses offer several key contributions to resilience. Firstly, they allow for year-round cultivation despite cold, variable winter weather, diversifying the food system and improving its reliability when outdoor growing is impossible. Secondly, solar-powered heating systems eliminate or drastically reduce fuel or electricity bills typical for winter greenhouse heating, reducing operational costs and shielding farmers from volatile fossil fuel prices and energy supply disruptions.
Thirdly, the use of thermal storage and ground temperature stabilization boosts environmental sustainability and system reliability. Utilizing climate battery concepts or geothermal principles, these greenhouses efficiently stabilize internal climate with low energy use. Lastly, the reduced environmental footprint comes from solar heating and geothermal techniques that decrease or eliminate greenhouse reliance on natural gas or other fossil fuels, helping farmers transition to renewable energy and lower carbon emissions.
In June, a tornado swept through southeast Minnesota, causing damage to Owl Bluff Farm, including the destruction of two high tunnels and the peeling of a roof off a storage shed. Remarkably, the deep winter greenhouse left nearly untouched after the storm, testifying to its resilience.
Despite the setback, Owl Bluff Farm's owner and operator, Carrie Calvo, expressed gratitude for the safety of everyone involved and the help received from neighbors. The farm started selling produce at a small farmers market and a local grocery store, and has since expanded to include restaurants and other opportunities.
Farmers like Calvo are turning to deep winter greenhouses to hold their ground in the face of Mother Nature's unpredictability. This approach not only buffers against weather extremes but also extends the growing season, lowers heating costs, and provides a stable local food supply even in harsh winters. In southeast Minnesota, where winters can be severe and food security intermittently threatened by extreme weather, such greenhouses therefore provide a sustainable, cost-effective solution for continuing fresh food production during the off-season, enhancing both farm viability and the resilience of local food systems against climatic challenges.
- Carrie Calvo, the owner of Owl Bluff Farm, is employing environmental-science solutions such as farm-scale deep winter greenhouses to combat climate-change impacts like cold winters and unpredictable weather, thereby ensuring year-round production and reducing dependence on fossil fuels.
- The implementation of these innovative greenhouses, designed with solar power and thermal storage for heating, has proven to enhance the resilience of the farm in southeast Minnesota, as demonstrated during the June tornado when the greenhouse left nearly untouched while other structures were damaged.
