Re: My semi-pit banana greenhouse
 

Just wanted to share an update.

I've currently got 5 bunches of Dwarf Orinoco and 1 bunch of Dwarf Brazilian. Several other DO's are looking suspiciously close to throwing buds, as are my Gluay Kai, Cocos (Dwarf Gros Michel), and SH-3640.

Here are some assorted pics. The 1st one is the Dwarf Brazilian, which I've transplanted 3 times and pruned/chopped back several times (thus the small bunch); it's only about 5' tall, but it's also buried 2' deep in the ground, so it's actually 7' tall from the top of the corm up.

Re: My semi-pit banana greenhouse
 

Bump!

Re: My semi-pit banana greenhouse
 

Greenfin, what was the lowest it got in the actual air above the ground in your pit greenhouse? I am trying to figure out how cold it can get with pstem survival. My pit greenhouse got down into the 20's last winter a couple of times, but I am fixing to put another poly layer on it with an inflater. Wondering if I should try to plant a few dwarf varieties in there in the ground, but dont want die back. Thinking of storing potted nanas in there as well, with just burying the pots in piles of leaves with the aim to get pstem survival. Also, how long did your Dwarf Brazilian take to ripen, I read it takes a while.

Re: My semi-pit banana greenhouse
 

Interesting....

I guess it was in palmtalk.org where a member

built a submerged/underground greenhouse.
The problem came during the rainy season>>>>>:rollerbananadone::03:
He couldnt stop the water from coming in.

Re: My semi-pit banana greenhouse
 

I did have a little bit of water come in, but not during normal rains. It was only when we got 4 feet of rain in 90 days (very unusual) that water started trickling in one time. If the pit was very deep, say 4 feet or more, or the water tables are high, I can see flooding becoming an issue. Overall though its worth it, it stays much warmer than outside. Single layer polly film does not keep in much heat at all on its own at night, maybe a few degrees higher, but daytime is another story. Underground it stays much warmer and the heat radiates into the greenhouse.

Re: My semi-pit banana greenhouse
 

The lowest air temp was in the upper 30's. Dwarf Orinoco pstems don't lose any height from those temps, but I do manually chop them back some at the end of winter to try and give them more headroom (since I have a low ceiling) to push out a few more leaves before they flower in the spring/summer. Cavendishes die down to the ground every winter; heck, they seem to pack it in and start dying as soon as the temps drop below 50F.

There's a dramatic insulation difference between 1 layer of plastic and using an inflated double-layer. When I added a 2nd layer to my first tunnel 5 years ago and inflated the gap, the nighttime low water temps inside went up 10-12 degrees.

The Dwarf Brazilian suffered a broken pstem soon after that pic was taken and never ripened its fruit. I thought I had it adequately supported, but the pstem snapped at ground level. I have since built a bigger pit greenhouse and have 2 mats of DB growing in there, but it'll probably be next spring/summer before I'll harvest anything from them.

Re: My semi-pit banana greenhouse
 

BTW, to share an update, I've mostly converted this semi-pit tunnel greenhouse into a 'fig house' and have moved most of the bananas into a bigger new pit tunnel greenhouse. There's only a small patch of Dwarf Orinocos remaining in there, but they've got 5 bunches hanging.

The new pit greenhouse is about 80' long x 17' wide x 11.5' tall (inside height), and the pit is around 4' deep. This will finally give me the headroom to allow some of the dwarf varieties to flourish, and to give me a punchers chance at getting fruit from my bigger projects like SH-3640 and Pisang Ceylon.

The new tunnel will also be holding almost 12,000 gallons of water in various pools, and since I'm going to be maintaining those water temps above 50F (probably above 60F) over the winter, the internal environment should stay warm enough for the super cold-sensitive AAA bananas to flourish.

Here's what I've got started in the newest greenhouse, with the number of mats in parenthesis if greater than 1 (pics to follow, maybe tomorrow morning when it's not so hot in there):

Dwarf Cavendish (5)
Dwarf Orinoco (5)
Dwarf Red (2)
Dwarf Namwah
Dwarf Brazilian (2)
Grand Nain (3)
Williams Hybrid
Glui Kai/Pisang Mas
Cocos (from Encanto Farms...is it the real deal?)
SH-3640 (2)
Pisang Ceylon

Between the pools and those bananas, almost all the space is already taken. But I still have a prime location reserved for Highgate and an area set aside for a couple of orange trees :)

Re: My semi-pit banana greenhouse
 

As I noted above, this semi-pit tunnel greenhouse is on its way to becoming primarily a fig house. I've been moving all of the bananas out and into a new, larger greenhouse that I've just built. There is still a strip of Dwarf Orinoco bananas remaining, though, and they've currently got 5 bunches of fruit hanging.