The name sounds a little weird, but the concept is AMAZING! It’s a walipini! Have you ever heard of it before? This solves a lot of problems for us in the Northern Hemisphere.
A walipini is an underground greenhouse. In general, it’s a wide trench, six to eight feet deep, with a slanted, plastic roof. According to TreeHugger.com, you can grow plants in a walipini all winter long.
There are a few YouTube videos that I found interesting.
The Benson Agriculture and Food Institute has published a guide to building your own walipini. It’s definitely worth a look!