Northeast food crop producers are increasingly growing cold-hardy crops to meet local market needs for fresh foods. That’s where deep winter greenhouses come in. So consider this as a resource with “jumping point” links, courtesy of the National Center for Appropriate Technology and the University of Minnesota.

What’s a deep winter greenhouse? It’s a passive solar greenhouse designed to dramatically limit fossil fuel required to grow crops in northern latitudes. DWGs are oriented east-west with a south-facing glazing wall specially angled, depending on latitude, to maximize solar energy on the shortest day of the year.

Solar energy is stored in an underground thermal mass made up of an insulated rock bed that acts as a heat battery. Without additional lighting, DWGs in northern climates can be used to grow cold-hardy crops that thrive with minimal light, providing year-round production capacity. Well-suited crops include lettuces, herbs, brassicas, Asian greens and sprouts.

Here are seven resources that cover every DWG aspect:

• University of Minnesota’s Statewide Prototype Initiative is a good place to start exploring the potentials of deep winter greenhouses. It covers design and construction, marketing, production and educational videos.

• The Cold Climate Greenhouse Resource manual is a guidebook highlighting the successes and lessons learned by growers who have designed and built cold-climate greenhouses.

• NCAT’s Solar Greenhouses publication covers basic principles of solar greenhouse design, plus different construction material options. 

• The Deep Winter Greenhouse Enterprise Analysis examines the ability of deep winter greenhouses to be viable business models. Results are based on analyses of seven deep winter producers in Minnesota.

• Producers looking to grow mizuna, arugula and giant red mustard might want to check out Soil Nutrients in Organically Fertilized Potting Media under Greenhouse Conditions.

• In Deep Winter Greenhouse Producer Bios, case studies of three different producers address what inspired them to build a DWG and what drives them to produce, teaching lessons that only those with experience can tell.

• If you’re looking for a producer-written book, check out the Northlands Winter Greenhouse Manual. This is a Barnes and Noble link to an order form. The book provides detailed and easy-to-read construction specifications, plus production techniques for successfully growing crops.

Source: National Center for Appropriate Technology