There is a new hype spreading across the cooler parts of North America, one that has been popular in the mountainous regions of South America for sometime – underground greenhouses. That’s right, you can build an underground greenhouse which allows you to grow food year-round, no matter where you live! It’s simple to construct and can usually be built for under $300.
As published in Treehugger earlier this year, underground greenhouses are the new rage. In cooler climates, people usually have to forego farming and backyard gardens, farmers markets and fresh foods and get their food at the grocery store instead during the winter. Well, say goodbye to seasonal farming, with underground greenhouses, so simple to construct, almost anyone can grow a variety of food all year-round.
The hole needs to be approximately 6-8 feet deep and run as long as you have space for (anywhere from 5-100 feet or more). The topside is covered with greenhouse plastic and slants toward the southern sun in order to reap the greatest solar benefits. These underground structures are named walipini – an Aymara Indian word which literally translates as “place of warmth” as they can generate quite a bit of heat. Sometimes, people have to put ventilators of some kind in order to release some of the heat that can accumulate underground.
Used for over 20 years, at least, in South America, so as to increase food production during the coldest times of the year, walipinis came about and have spread in popularity as their simple structure and building protocol is discovered. The only issue to really look at is water drainage. The roof needs to be slanted into a run-off system so as not to accumulate water in the hole. Here is a short video from the inside of an underground greenhouse:
You can grow nearly anything in these below-the-surface greenhouses. Since it gets so nice and warm down there underground, even tropical plants and trees such as cacao, papaya, lemon and mangos could be cultivated – even in northern climates. How exciting is that? The low cost of building one of these brilliant farming mines is counting on the fact that you have strong arms to dig the hole. You may want to call in the neighbors for a joint digging project and agree to share the abundance from your underground treasure pit.
How does it work? Isn’t it cold underground? Apparently, not only do you have the greenhouse effect above, you also have the heat of the magma core of the earth which is tapped around four feet deep in the earth – keeping the hole between 50-60 degrees Fahrenheit at all times, at least. The Benson Institute on-line (listed in Sources below) has a free PDF explaining everything about how to construct an underground greenhouse and how it works. In their catalog they explain this underground heating source: “By digging the Walipini into the ground, the tremendous flywheel of stable temperature called the ‟thermal constant” is tapped. Thus, the additional heat needed from the sun’s rays as they pass through the plastic and provide interior heat is much less in the Walipini than in the above ground greenhouse.”
If you live in the Northern Hemisphere and love to garden, the walipini might be a cool new farming tool you can implement this year. Time to gather your neighbors, some shovels and start a digging! Yes, you can grow food year-round in your own back yard – underground with this amazingly simple and effective technique. For more information, visit the Benson Institute on-line.
Written by: Stasia Bliss