Wednesday, April 16, 2014

So What is a Walapini?

If someone threatens to kick you in your Walapini or afraid, ....but it is otherwise a very interesting thing to explore. 
Basically this is an underground, or rather a below ground level greenhouse. 
Just a general description here, then you should search either the regular Internet or You Tube for more info.

The basic idea is that you dig a generally east west aligned trench in the ground, about 8 feet wide by whatever you have room for or need of.
You remove the topsoil and hold it aside.  Then continue your dig, piling the subsoil on the north side of the trench.  (This will not work in a low lying area or in an area with a high water table.)
It may be wise to plan on some sort of stone, pressure treated or other lining for the walls.  This might also be a good time to line the north wall with black painted barrels of water as heat storage.
Then you return the top soil to the bottom of the trench, augmented as necessary with fertilizers, manure, peat, etc..
You must make the north side of the trench(In the Northern Hemisphere) at an angle above the southern side of the trench, so as to allow the sun to hit the roof at 90 degrees during the winter Solstice.  The angle of the wall to the level of the roof should be the latitude you are at, I think.  As an example, the north side of Eastport, Maine is approximately half way from the equator to the north pole, so that is 45 degrees.
You lay beams or rafters from the high side to the low side of the bank, and cover the roof with a double layer of plastic, corrugated plastic panels etc..  You must allow for drainage away from the greenhouse on the south side, around the greenhouse on the north side, and for easy snow removal.  Laying sod or planting cover crops on the berms will help with erosion from water hitting the bare earth.   This may be a good place to plant Mint, poor soil loving herbs, day lilies or plants that you might hesitate to grow elsewhere because of their spreading tendencies.  Strangely snow removal would be easier as you go farther north, as the angle of the roof must get higher.
Then you build a bulkhead or trench entrance with a door.  You can keep livestock inside...Chickens, goats etc., and get extra crops of flowers and vegetables from this, and cold weather crops could be year round, like peas, cabbages, some root veggies and lettuces.(Note that some of these will grow well in the cold, but need warmth to germinate{peas for one} your research!)(Note also, that horses require much more height, possibly 10 feet or more to the bottom of the rafters.)
This could be heated, but quite economically, as the solar gain and the ambient warmth from the earth will be a great help.
Look it up and buy a great book on the subject as there will be issues, best addressed by an expert on the subject.
This is not, unfortunately, a low visibility project, but siting the greenhouse and entrance door on the south side of your property from your house and drive, and planting heavy cover crops on the berm facing the house, might hide it from intruders in an area where hillocks are common in the landscape.  Any outbuilding with a path leading to it will be noticed, however.

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