As more people become aware of the importance of growing their own food, social media has become a primary way ideas are shared. One of these ideas which is often seen on Facebook and Pinterest is the walipini underground greenhouse.
This greenhouse claims to grow food year-round and only cost $300 in building materials. For lots of gardeners, particularly those in cool climates with short growing seasons, a greenhouse is almost a must-have. Let’s take a look at the advantages of an underground greenhouse:
Takes advantage of thermal mass. When you dig down even just four feet, the temperature changes dramatically. Frost lines generally are three to four deep, so a six to eight foot walipini is completely protected from frost. One walipini owner claims that his greenhouse keeps pretty steady 70 degree Fahrenheit or warmer temperatures when it’s 10 degrees outside. Because underground greenhouses are warmed by thermal mass on all sides, you really can’t lose any warmth compared to a traditional greenhouse.
Effective in almost any climate. Walipini and other pit-style greenhouses are effective nearly everywhere. In fact, many of the early designs for these greenhouses originated in very cold climates like Canada. Of course, you won’t be able to get super-hot temps in a cold climate in winter, but it will get warmer than a traditional greenhouse. Many countries outside of the United States swear by these designs, particularly gardeners in China.