Hey all; I am really intrigued with the old concept of a pit greenhouse. The modern version of this is called a 'Walipini'. There is quite a bit of info on line. There are pros and cons-so check it out.
A greenhouse that suggests growing year round with out power. Basically:digging pits 4 to 8 feet deep into the ground. The pit can be as long as the family needs and runs parallel with SW sun. This pit requires to be fairly wide as the wall on the SW side creates shadow. The pit is than covered with glass, poly, or the like at a angle/degree appropriate to your location. The exterior of the north wall is berm. The interior of the North wall reflective.
There are many cut away images to show better than I can explain. A good example of a existing pit was 75' X 20'. Some people combine this concept with hot boxes. Some include livestock or fish due to the heat. The angle/pitch of your roof is paramount-so please look at where you live. In Alberta here, I would require a fairly steep roof to capture sun. But this greenhouse has promise over a regular above ground greenhouse.
Check it out and please add any further info you find. I want to get as much info as I can about this type of greenhouse prior to digging and spending time and money-the more people looking into it and adding their own experiences the better.
Here's a starting point for everyone. www.inspirationgreen.com/pit-greenhouses.html
Hmmm sounds like an empty pool could be converted. LOL
Goldie, yes!!! They have a example of that. It in fact is a great already made dug out-if your lucky enough to have that already.
Thanks for sharing Dakota. Some fantastic ideas here appropriate for us here in Canada. Ver
Its a great idea...BUTTTT...Im not sure its suitable for Canadian soil. One of my grandest follies was burying a cube van to use as a cold storage. The earth crushed it from the sides. Over time, I have come to understand that land is sort of like water...because it is filled with water. It flows. I will eventually try another cold storage...but it will be above ground. Tires filled with dirt with dirt piled up the sides. This keeps it from flooding in or moving due to soil flow. The same idea may work for your thermal mass greenhouse...or maybe an above ground fallout shelter. I'll never dig something into the ground again. Hope this helps
I have a Tactical Harness and I have a Tool Belt. The Tool Belt is more Useful.
Any way you can get below ground level it's going to help. You're spot on about the roof angle but our cold temps more than make it worthwhile.
I think one key point for insulation would be to keep the ground surrounding the hole dry by slope and water barrier on the surface. Wet soil is a conductor of heat, dry soil an insulator.
you have to be careful with concrete pools or the walls can cave in
if there is no water in them depending on the water table level
so I can understand this happening with all sorts of things.
I'm thinking cold storage needs to be carefully planned out and so does an in ground greenhouse
How about a cold storage that is ground level on one side and the other side is buried into a hill ?
Would that work for a greenhouse ?
well knock yourself out, but I suggest you pass and just build a above grade one, heat wont be a problem with a below grade one done right, light will. I would say from Calgary north, maybe the border north you just dont get enough light, build a above grade green house but well insulated, bermed, and extend the growing season into the 1first of Nov, maybe middle, then shut it down. start your seedlings again inside the house in march, move them to the green house in April or so or whatever is most practical for your area. I know its not worth the effort for much of Alberta, not unless you are prepared to go with grow lights through the months of Nov, Dec Jan, Feb and march, and if you do, running them on the scale needed wont be cheap. In fact I suspect the cost would buy you all the vegtables you could want through the winter, though maybe your looking for a more profitable crop?
Then go with raised beds like this but with this type you can place poly over top so you have a mini greenhouse within a green house.
Same with these
the blue barrels are cut like that water tank so polly can be put over them, and everything raised...bending over or crawling around on the ground to garden is for the birds...or those with young backs and knees
and what c5 said about flooding you should pay attention to...you can do it without having it flood but it takes a little practice to get it right...built some underground shooting bench's once, maybe 5feet below grade and back into a hill., roof done in dirt with doors on the front that flipped up and you could shoot out through, inside with two shooting benches, and done in cedar..a real nice man cave...for about a year, then next spring came and the snow melted and it became a 5 foot deep mud hole.
In fact there was a fellow in Manitoba who had his construction of one up on the net...it was huge and deep..I was talking with him through the build (this was maybe 6 years back)...then come next spring..he took his web site down and I lost contact...while I dont know what happened..I suspect after the spring melt he had a swimming pool, not a underground greenhouse
Give a man a gun, and he can rob a bank. Give a man a bank, and he can rob the world.
I did end up doing above ground greenhouse with raised boxes in my garden(regular way for us). I cover with hoops when the weathers colder-like now! The greenhouse will house some more spinach and lettuce for a month or two more. I was please with the harvest and will likely continue this route. We also have some old windows (one of our group members brought out) we can use next year for cold boxes.