My friend Jennifer sent me a link this week all about something I’d never seen before: underground greenhouses. Known as a walipini, these dugouts with plastic roofs were first built in the mountain regions of South America to allow people to grow crops almost year round. Jennifer wanted to know my opinion about building one here in Alberta.
First of all, thank you, Jen, for holding my opinion in such high esteem. Second, I really don’t know. The idea intrigues me; it’s almost like a walk-in cold frame, and you know how I love cold frames. Walipinis take it to the next level though, using the natural warmth of the earth to heat the space, not just the sun. While they would require a lot of labour to dig, and a lot of space to accommodate, the materials could be lower in cost than a traditional greenhouse set up. Also, I have many neighbours who have had ‘kit’ type greenhouses blown into Saskatchewan or smashed by hail. Digging into the earth seems like a logical way to avoid our gales.
As long as you could build a roof to withstand those winds, as well as the heavy, wet snow we can get. A really solid roof would be absolutely necessary. Could we do it?
A quick trip around the internet revealed several variations of dug greenhouses, the “earth sheltered” variety being fairly common. Everyone seems to have their own special considerations to the design, but the consensus seems quite positive that it is entirely possible, even here.
Luckily for me, Jennifer has a willing relation with a backhoe, a lot full of lawn she wants to transform, and a husband who’s thinking through the roofing questions.
I get to watch and learn.