Underground greenhouses are a great way that you can try to grow better, because the underground greenhouse allows for you to grow in much colder temperatures and climates. When you go roughly six to eight feet below the surface, the temperature usually stays within the range of 50 and 60°F and this makes it ideal for growing.
Whether it is too hot or too cold, an underground greenhouse might be a great way to establish a better growing environment for your crops and plants. The idea for underground greenhouses has been around for many years and farmers all over the world have employed this type of structure so that they could grow their own plants and crops.
Using underground greenhouses is an easy way to extend the growing season and possibly give crops a good boost. These types of greenhouses are also known as a walipini which is an indian word for meaning 'place of warmth.' And this type of growing will allow you to maintain your crops all year long, regardless of the outside weather conditions.
In this set-up above for example. the natural clay is going to do really well with absorbing the daily heat. When using a pit-style greenhouse, the large amount of thermal mass (water, stone, soil) is very important; along with the structures position to the sun. Some individuals have been able to construct their greenhouse for less than $300, and when it comes to how much the model might cost you it really depends on what materials you have to begin with.
The underground greenhouse is going to use natural resources to be able to establish a well-lit, stable, and warm environment for you to grow in. If built successfully, the walipini will allow for natural insulation and can even store daytime solar radiation. It's important to keep waterproofing in mind, along with drainage and ventilating, but this type of greenhouse can be much more effective than the traditional ones which aren't able to provide a growing environment that will be as effective in harsh climates. The underground greenhouse model is almost universally viable.
see:
http://www.treehugger.com/green-architecture/build-underground-greenhouse-garden-year-round.html