Growers in colder climates often utilize various approaches to extend the growing season or to give their crops a boost, whether it’s coldframes, hoop houses or greenhouses.
Greenhouses are usually glazed structures, but are typically expensive to construct and heat throughout the winter. A much more affordable and effective alternative to glass greenhouses is the walipini (an Aymara Indian word for a “place of warmth”), also known as an underground or pit greenhouse. First developed over 20 years ago for the cold mountainous regions of South America, this method allows growers to maintain a productive garden year-round, even in the coldest of climates.
Here’s a video tour of a walipini that even incorporates a bit of interior space for goats:
How a Walipini works and how to build one
© Benson Institute
It’s a pretty intriguing set-up that combines the principles of passive solar heating with earth-sheltered building. But how to make one?From American sustainable agriculture non-profit Benson Institute comes this enlightening manual on how a walipini works, and how to build it:
The Walipini utilizes nature’s resources to provide a warm, stable, well-lit environment for year-round vegetable production. Locating the growing area 6’- 8’ underground and capturing and storing daytime solar radiation are the most important principles in building a successful Walipini.
The Walipini, in simplest terms, is a rectangular hole in the ground 6 ‛ to 8’ deep covered by plastic sheeting. The longest area of the rectangle faces the winter sun — to the north in the Southern Hemisphere and to the south in the Northern Hemisphere. 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.
SilverThunder/via
This earth-sheltered greenhouse taps into the thermal mass of the earth, so that much less energy is needed to heat up the walipini’s interior than an aboveground greenhouse. Of course, there are precautions to take in waterproofing, drainage and ventilating the walipini, while aligning it properly to the sun — which the manual covers in detail.
Best of all, according to the Benson Institute, their 20-foot by 74-foot walipnifield model out in La Paz cost around $250 to $300 only, thanks to the use of free labour provided by owners and neighbours, and the use of cheaper materials like plastic ultraviolet (UV) protective sheeting and PVC piping.
Cheap but effective, the underground greenhouse is a great way for growers to produce food year-round in colder climates. More over at the Benson Instituteand the Pure Energy Systems Wiki.
[Via Treehugger.com]
What do you do for pollination?
For root and leaf veggies, that is not an issue. For fruits and veggies, a fan may be sufficient to move the air (and pollen) around. Or you may choose to pollinate the plants manually, which is more tedious. There are articles on the internet that will teach you this method. Search on "manual plant pollination" in your fav search engine.
I've built two of these in the last 5 years and absolutely swear by them. Lots of initial work, but once done, amazingly efficient. Throw in a few solar-powered fans to regulate heat and air flow, and you'll never go back to "regular" greenhouses!
The video was spazzing all over the place, none of it was in focus when I viewed it. I even tried stopping the action and doing slow jumps at a time, but in the end I could not really make out much. However, the two still shots were nice and clear. Maybe instead of a herky-jerky phone-cam you could get a tripod and a camera or even stills shots from a phone (with a tripod) and put those all together so we can see what you have really got going. The concept sounds very interesting and I would like to be able to see and learn more.
Thanks.
The concept is quite interesting and cheap too, I mean only $300 a year for an underground greenhouse doesn’t seem bad at all. But it really takes a lot of efforts to built a underground greenhouse. I wish all the very best to all those who are planning to get an underground greenhouse built. Though I love gardening too but I have preferred to get a Harmony Series as its just the right size to begin greenhouse gardening and perfect for smaller yards or patios. I have bought a 6′ x 4′ Silver greenhouse from http://envirotechgreenhouse.com/harmony-series just for $479. And the features includes galvanized steel base, magnetic door catch, left or right swinging door, roof vent and rain gutters. Moreover rust resistant green powder coated aluminum frame ensure years of use and very low maintenance.
For root and leaf veggies, that is not an issue. For fruits and veggies, a fan may be sufficient to move the air (and pollen) around. Or you may choose to pollinate the plants manually, which is more tedious. There are articles on the internet that will teach you this method. Search on "manual plant pollination" in your fav search engine.
I want to build a Greenhouse like this. It's a cool structure