A Walipini is an underground greenhouse that allows gardening throughout the year, even in winter. The heat is stored all day and distributes the heat at night. It is possible to keep a constant temperature during 24 hours thanks to the glazing which makes it possible to have a greenhouse effect and to the thermal inertia due to the depth. Therefore, plants are never subjected to large temperature differences. It was in the 1990s, in the heart of the most mountainous regions of South America that this form of agriculture developed. The challenge is to have a productive vegetable garden all year round. The most interesting thing is that it can cost around 250 euros, which is an enticing price for anyone who wants to have vegetables all year round!
How to make one.
You need a good placement that has lots of sun and where you can build a slant roof and able to dig into the ground.
You need to dig a rectangle which is about 2.5 meters deep and at least 1.5 m above the water table. Then cover with a plastic sheeting. The walls must also be created with dense material such as stone or raw earth. This absorbs large amounts of heat.
A few photographs of a underground greenhouse:
Source : PréventionSanté