Tuesday, March 26, 2013

Semi-pit tunnel greenhouse project

I dug out this semi-pit greenhouse by hand last fall/winter using my trusty garden shovel and wheelbarrow. It was a ton of work, so if you're thinking about one of your own, I would recommend using a faster/easier method if circumstances allow.  It's about 55' x 14' x 7.5' and was built using 20' lengths of 1.5" PVC.  It's about 2' deep and is covered with two layers of greenhouse plastic (inflated).  I spent $1,500 or so total and put in around a million hours of labor.

The lone banana in the pic above is a Dwarf Orinoco that I transplanted there during the winter to provide some size perspective and to see if it would survive.  It was already yellowed and dormant when I moved it in, and it stayed that way until March or so, when it started growing again.  In the meantime I grew greens:

The coldest it ever got at ground level was 36F (outside temps were around 0F), which was great since it was entirely unheated.  Next winter I'm hoping to keep the minimum temp around 45F by adding several thousand gallons of water (in tanks) to catch and radiate warmth.

As it became too hot for growing greens in the tunnel in early spring, I started moving some bananas in:

Then in early May I added some more:  

Here they are at the end of May (left side, front to back, goes Raja Puri, Gros Michel, Double, Williams Hybrid, Dwarf Orinoco, Dwarf Cavendish; right side, front to back, goes Grand Nain, Kluay Khai, Dwarf Namwah, Misi Luki, Dwarf Brazilian, SH-3640):




I'm hoping to have the money to put up a much taller greenhouse (12-15') this fall to house most of these; if not, I'll whack 'em back and overwinter them in there, then move them outside first thing next spring.

Hope you enjoyed the tour :)