Giving a whole new meaning to the term underground industry, a walipini is a South American technique of taking advantage of an endless source of heat for grows in cold climates. Think of it as a greenhouse that’s sunken into the ground so its walls are the earth around it. Some radioactive decay and a little energy left over from the formation of the planet pushes out 47 terawatts of energy through the Earth’s crust making the air temperature 55°-60° F in any hole dug five to 10 feet below the frost line, anywhere on the solid surface of the Earth. This ingenious method can be used to create a permaculture sustaining all your vegetable needs year-round, and yes, it’s perfect for growing some monster weed plants in chilly climates.
Over at the Dragonfly Earth Medicine farm in British Columbia they started off with a few above-ground greenhouses but when gradual climate change brought the heavy fall rains in as early as August, they started experiencing issues excessive moisture can bring such as mold growth. They thought, “What if we go into the ground?” It was out of pure experimentation but they happened to strike gold; out of their three greenhouses the one underground, the walipini, allowed for the most vigorous plant growth.
Using their own strains they’ve been working on for over 25 years that are well adapted to the chilly, humid climate of the Northern Pacific region, Dragonfly has been able to grow some of the biggest cannabis plants we’ve ever seen. They start their seeds off indoors at the end of January and begin moving them out to a greenhouse, still in the pots, under supplemental lighting once the frigid grip of the Canadian winter loosens up. Being outside their plants get “hardened off” (accustomed to cold nights) which is important for healthy plant growth in the strains they have.
Starting outdoor plants off in January-February is typical for outdoor plants so, where does the walipini come in? A sunken, naturally heated greenhouse allows the plants to be outside under those powerful solar rays for longer than they would otherwise be able to in a chilly climate. That extra long growing season lets their plants get up to 15 feet tall, with massively wide stalks yielding four to five pounds of ganja per plant.
Stay tuned for a more in-depth description on the basics to building your own walipini.