The Green Underground
~ Samantha Lewis
Greenhouses are a lot of fun for both the homeowner and grower out there. They look unique, they serve a huge purpose when it comes to ecology, growing food, maintaining flowers, using solar energy to increase growth, and helping to save the soil. In fact, the list of benefits a greenhouse brings to both you and the world is a really long one. But green is not only for aboveground. In fact, underground greenhouses are becoming all the rage, and are super cool to build.
When it comes to cold climates, there are growers who utilize all types of greenhouses to increase the time of their growing seasons and boost the crops they need to produce. There are coldframes, hoop houses—tons of choices where greenhouses are concerned. But, as with anything else, money comes into play.
The mammoth structures that most are familiar with when thinking about greenhouses are usually extremely costly to build; not to mention, the high costs of attempting to keep the structures heated when Old Man Winter comes along. But one of the most popular greenhouses that takes care of the worries, completely affordable and extremely beneficial, is called a Walipini, which comes from the Aymara Indian word for a “place of warmth.” THIS is the underground greenhouse.
It was over two decades ago in a truly freezing cold region of South America, that the underground greenhouse came to be a part of everyday life. Up in the mountains, the underground greenhouse was a huge resource that allowed growers to have a productive garden all year long, no matter how many feet of snow fell on them.
And building your own Walipini is a whole lot of fun. By taking the resources that nature and the earth already provide, the underground greenhouse provides a warm, well-lit and completely stable environment to produce vegetables. And to begin construction, all that needs to be done is to locate a growing area 6’- 8’ underground that can capture daytime solar radiation and store it.
A rectangular hole in the ground dug 6’ to 8’ deep is covered by plastic sheeting, with the longest area of the rectangle facing toward the winter sun. Using a thick wall of packed earth at the back of the building, a lower wall is created at the front; with one short and the other high, a perfect angle is made for the plastic sheet roof that seals the hole in the ground, and provides an insulating airspace between the two layers of plastic. The two layers come from a sheet on the top and another on the bottom of the roof/poles, which allow the rays of the sun to penetrate and create that warm and stable environment to always have plant growth.
It is not a far out idea. After all, the earth is a true greenhouse already, and the grower can tap into the thermal mass of the earth by growing in an underground greenhouse. Less energy is needed to keep the Walipini’s interior heated, which saves massive bucks, instead of attempting to heat that aboveground greenhouse and watching your savings account decline rapidly. Waterproofing, drainage, and ventilation – these are the three things to keep in mind when building the Walipini, so make sure it is properly aligned with the sun while building to avoid any problems later on.
For anyone who is interested in bringing the idea to their own backyard, Walipini field models, as well as construction manuals, can be found from various places on the Internet. A place called the Benson Institute even has a 20-foot by 74-foot Walipini field model located in La Paz – a total cost of less than $300 to create.
Kind to the wallet and extremely efficient, it doesn’t take long to realize that the Walipini is the only way to grow.