How to build an underground greenhouse

The underground greenhouses are an efficient and economical alternative so you can grow food all year round.

The underground greenhouse is a rectangular hole dug in the ground with an average depth of three meters, covered with plastic. It is designed to keep the temperature constant, about 16 ºC. To achieve this, you need to select a location that is sunny all year round, in addition to being at least one meter deep. In this way, the energy of the sun and the protective capacity of the earth are used.

Important specifications must be taken into account for its construction. For example, the doors should be tilted and oriented so that the roof remains without collapsing. In relation to the inclination, it is recommended to keep 39 °, from north to south. Later, small holes are made, some of them will be used for further drainage. Finally, the structure must be strong to withstand rain and snow.

The construction of the walls can be done with the same soil as that obtained when digging the pit. The north wall should be higher than the south facing wall; It is a measure to be taken with the seasons. For example, in winter you need as much heat from the sun as possible, while in summer the sunlight will be reflected. It is then covered with plastic, in order to prevent water infiltration and avoid heat loss.

The roof that seals the hole should also be covered with two layers of plastic, one above and one under the roof. When the sun’s rays penetrate, a warm environment conducive to plant growth. Underground walls help retain moisture and heat. The width and length of the rectangular hole can be changed; the important thing is that there is enough space for each crop.

Advantages of underground greenhouses.

  • The temperature remains constant and high during the winters.
  • During the summers, the temperature stays cool and the humidity is much higher.
  • You can grow year round.
  • The cost of construction is low and the production is high.

If you were interested in this type of greenhouse, here are the full instructions: fao.org