Three Sisters Farm is a five-acre permaculture farm in Mercer County, Pennsylvania. For more than 20 years, the farm has provided produce for markets throughout Western PA, including Pittsburgh.
The Bioshelter at Three Sisters Farm
At the heart of the farm’s operations is the bioshelter. This unique structure is part greenhouse, part chicken coop, part hot tub and all permaculture.
The main consideration for the bioshelter is the capture and retention of heat and the ability to exhaust it when it is not needed. This bioshelter is a far cry from the plastic-film covered hoop houses heated with coal, oil or gas. With careful design and attention to the operation of the system, the bioshelter stays productive through the coldest of months.
The bioshelter is oriented to the south to capture the low-riding winter sun’s warmth. Also along the southern side is a long line of cold frames hinged to the bioshelter wall. Heat rises through the two-story structure, and with the help of air pumps the warmth is moved through the growing beds. The shelter has a gravel floor, masonry-lined beds and steel drums scatted throughout. All of this mass serves as a heat sink to capture the sun’s energy when its available and release it long after the sun has given up. With this passive and active solar heating and supplemental heat from a wood stove, the heating needs are satisfied.
The bioshelter houses salad greens and plants that attract beneficial insects, which helps to keep the pests at bay. Here you can see Darrell Frey harvesting a salad mix.
Of course, as in all good permaculture design, there is redundancy and the stacking of functions throughout the ecosystem of the bioshelter. The chickens also provide warmth to the structure in addition to carbon dioxide and manure for composting, not to mention eggs. There are also built in compost areas under the seedling benches which provide heat and carbon dioxide as well.
To retain heat the structure is well insulated and has additional rooms to the north to act as a buffer against the cold north winds. Click Here to see a floor plan of the bioshelter.
According to Darrell Frey, the owner of Three Sisters Farm, zone 1 of the bioshelter is defined by the reach of a 100 foot hose from the spigot. Within this area are several areas of interest including production greenhouses, the chicken yard, the cold frames, a cool micro-climate on the north side of the shelter and a peaceful spiral garden with many useful trees, shrubs and herbs.
The spiral garden, as it was many years ago, still sits off the west end of the bioshelter.
Other aspects of the farm include orchard fruits, outdoor cropping, aquatic systems and the cultivation and sales of native plants that make the farm their home. Throughout the five-acre farm natural patterns are used to advantage, reducing the labor input while encouraging greater productivity.
Three Sisters Farm offers consultation on organic farming, greenhouse design and management, constructed wetlands for waste water treatment, ecological land-use planning, permaculture designs, gardening, landscaping, native plants and more. The farm also offers Permaculture Design Certificate Courses. To learn more about workshops, Click Here.
Please support our local farms, visit Three Sisters Farm’s Website and keep your eye out for Darrell’s book which is going to be published Fall 2010.