One of the speakers was a grower who was sharing his experiences building and using a Chinese Solar Greenhouse.
I first heard the term, “Chinese Solar Greenhouse,” from our former State Vegetable Specialist, Dr. Sanjun Gu, at the Great Plains Growers Conference several years ago. Dr. Gu is from China, and had a lot of photos of this interesting technology.
This technology allows producers in China to grow warm season vegetables during the winter months, with no additional heating. Can you imagine growing tomatoes in January without extra heat? They are doing it in China, at latitudes similar to ours. In other words, it is in a cold part of China, not the tropics.
How do they do this? The key is good insulation. The greenhouses run east and west. The north side, as well as the east and west end walls, are very thick, made of earth or some other material to provide insulation as well as storing heat. The south side is covered with plastic, but is covered at night by a straw mat, which provides further insulation to be able to retain the heat at night that was gained during the day.
A grower north of Springfield heard Dr. Gu’s presentation, and was intrigued enough to build a Chinese Solar Greenhouse. He has followed most of the design principles, although he has not found an insulating material to cover the greenhouse at night. That has meant a few nights where the temperature inside approached freezing, which required additional heat.
The grower has tried several crops, including early and late tomatoes, cucumbers, and bell peppers, which lasted until Christmas. He also has grown carrots, head lettuce, kale, chard, celery, parsley, and various salad greens which have been seeded and harvested all winter long.
In addition he has tried ginger, which does quite well. Chinese Solar Greenhouses certainly have a lot of advantages, especially if a grower has a market for crops during the winter. There are a few disadvantages, including the extra cost of construction. It will be interesting to see what this grower’s conclusions will be after a few more years of using this structure.
(By: Tim Baker, Extension Professional and Horticulture Specialist)