Build a $300 Underground Greenhouse for Year-Round Gardening
21.08.2024 - 05:05
/ treehugger.com
Growers in cold climates often utilize various approaches to extend the growing season or boost their crops, including cold frames, hoop houses, and greenhouses. Greenhouses—typically glazed structures— are often expensive to construct and heat throughout the winter. But, they have their benefits, which is why underground greenhouses can be viable alternatives.
The walipini (an Aymara Indian word for a «place of warmth»), also known as an underground or pit greenhouse, is a much more affordable and effective year-round option than the traditional glass greenhouse. First developed for the cold mountainous regions of South America, the in-ground greenhouse allows growers to maintain a productive garden 365 days a year, even in the coldest climates.
An underground greenhouse (walipini) is an intriguing set-up combining the principles of passive solar heating with an earth-sheltered building. But how do you make one? American sustainable agriculture non-profit Benson Institute provides the enlightening manual below on how an underground greenhouse works and how to build one:
Benson Institute's earth-sheltered greenhouse taps into the earth's thermal mass so much less energy is needed to heat the walipini's interior than an aboveground greenhouse. Of course, there are precautions to take in waterproofing, drainage, and ventilation, while aligning the greenhouse properly to the sun—which the manual covers in detail.
Best of all, according to Benson Institute, its 20'x74' walipini field model in La Paz cost just around $250 to $300 to build, thanks to help from the owners and their neighbors, and the use of cheaper materials like plastic ultraviolet (UV) protective sheeting and PVC piping.
Cheap and effective, an