One day I got a call from an old friend who invited me to join him with some friends on the following Saturday to view a Walipini. “Sure” I said, having no earthly clue what he was talking about. I had to quickly Google the word after the phone call to see what this exotic thing was that I would be viewing.
Within minutes I was spell-bound learning about an interesting concept in earth sheltered gardening. A Walipini is essentially an underground greenhouse. Some refer to it as a pit greenhouse. The one I viewed first online was developed for people in countries with climates like they have in La Paz, Bolivia.
Since I am passionate about sustainability and since I have toyed with the idea of building an earth sheltered home for years, the Walipini really captured my imagination. While I am always looking into eco friendly products for green living, the thought of creating my own garden underground was quite an exhilarating proposition. I could already see my own custom walipini with an extended tool room and place to put my yoga gear.
The Benson Institute at BYU seems to have pioneered the idea in hopes of helping people in third world countries to enjoy a more sustainable method of growing food. A traditional Walipini, in simplest terms, according to the Benson Institute website “is a rectangular hole in the ground 6 ‛ to 8’ deep covered by plastic sheeting… A thick wall of rammed earth at the back of the building and a much lower wall at the front provide the needed angle for the plastic sheet roof.
This roof seals the hole, provides an insulating airspace between the two layers of plastic (a sheet on the top and another on the bottom of the roof/poles) and allows the sun’s rays to penetrate creating a warm, stable environment for plant growth.” The term “Walipini” comes from the Aymara Indian language which means “place of warmth”. The idea behind the Walipini is to harness nature’s resources by growing a garden about 8 feet deep into the ground. By so doing, one can combine daytime solar radiation with the heat that is rising up from the earth. Needless to say, high winds are also kept at bay.
It didn’t take me long to realize that the general principles could be applied in building an earth sheltered greenhouse in lots of different geographic climate conditions. I live in southern Idaho where the temperatures get pretty chilly towards the end of the summer. One of my great frustrations is to lose all my tomatoes plants just as they are starting to produce in large amounts. It occurred to me that a Walipini was the answer to a short growing season.
After viewing a large modified Walipini with my friends that Saturday, I had the bug and I had it bad. Within a few weeks I had found a contractor with a very large backhoe who agreed to dig an eight foot deep hole that was 20 by 30 feet wide. Over the years my wife and I had collected some very large windows which we used for the front.
A farmer who had large pile of two by sixes from a terminated project sold them to me for a song. I used them to construct the inner frame to hold the siding and support my convertible roof. Finally I secured some highly insulated side panels left over from the construction of a Family Dollar store. I now enjoy a much longer growing season for my tomatoes and year round gardening for my cold weather crops year round.
More about the walipini: Walipini Underground Greenhouses