bananas under plastic in cooler climates?
 

I'm playing around with dwarf bananas under plastic to see if I can get some commercial quality fruit from my dwarf plants in temperate New Zealand. I've been growing bananas for almost 20 years, and there are several cv.s that produce good fruit outside for me here, Pacha Nadaan, Misi Luki (NZ/Cal. form ex-Samoa) in particular. My main problem is that to produce in my cool temperatures the plants need huge amounts of inputs of time, fertiliser, and water. Under plastic they grow a lot faster and with less inputs, and I'm hoping to get some better fruit with less hassle.

Under plastic I have the following cv.s: rajapuri, Dwarf orinoco, Mahoi, various Dwarf cav types including Grande Naine (ex-Israel), a TC offtype of Aussie Mons Maree, and various subtypes such as Dwarf cav ex-Norfolk Island.

My climate is coolish oceanic temperate, USDA zone 10 as far as extreme cold goes, but with a mean annual air temperature of only 15C. Under a very simple plastic cover the daytime max temperature is consistently in the 30'sC in summer, and usually at least 20C in winter, but the nights cool off to ambient air temperature (mean minimum of 15C in summer, 6C in winter) within a few hours of sunset.

Are there any dwarf banana cv.s that don't mind a consistent 15C+ diurnal temperature range? Am I likely to get my ideal commercial-quality fruit in a very simple greenhouse structure without any night heating?

So far results are promising, after about 10 months under plastic some of my plants look big enough to start flowering. I have seen a banana grower in another part of NZ who put tall bananas under plastic and ended up with 200-300% height growth, but I'm hoping that will not happen with the dwarfs.

Any comments would be appreciated.



Cheers,


Ben

Re: bananas under plastic in cooler climates?
 

although I myself, do not have anything to add to this, it does sound like a very promising study for me to keep an eye on. Thanks for sharing what you are doing, I'm sure your work will be.....um....FRUITFUL! I will be highly interested in hearing the results and tweaks of this.

Re: bananas under plastic in cooler climates?
 

All I can say I wish you Luck! I don't think dwarf just grow 2-300%+ of dwarf size unless the other fellow didn't get what he ordered. :^)

Re: bananas under plastic in cooler climates?
 

My best cold producers (meaning only producers, so far) are Dwarf Orinoco, California Gold, Raja Puri, and Ice Cream, though not a dwarf.

I have the benefit of extra warm days 35-40C, but temps at night often fall to 10C with a 10 knot wind. In winter these stand unprotected down below 0 C, and come back to fruit the following summer.

Re: bananas under plastic in cooler climates?
 

Some time later ( I just got here):
I grew a variety of Australian Lady Finger that was recommended to me by David Austin for its tolerance of cold feet. I grew it in an 8m high conservatory in Inglewood. That is Taranaki; not Queensland. It reached the top and the leaves bent down and it fruited reasonably well. It may've done better with bunch covers.

If you're slow like me and still mulling over the idea of growing in a greenhouse, go for something around 10 – 15m or more high. A bamboo gridshell could be the most economic; classy; and perhaps also a tourist venture.

No such thing as a dwarf indoors!

I've found that growing outdoors, elevated soil temperature is important; as are bunch covers. This winter I'm trying bubble wrap augmented covers. You might consider creating an anthropic soil with charcoal amendments for aeration and favourability for mycorrhizae and thus water availability.
Smallish gardens in the forest shelter from wind chill; sloping toward the equator.

One other option is breeding along the lines of the “freeze thaw awakening method”
Kind regards,
Shem

Re: bananas under plastic in cooler climates?
 

I've been mixing some concrete. It gives me some time to think about this thread. That's not the only thing that concrete has to do with bananas. The concrete is for the abutments for a bascule.

My conservatory was a passive solar greenhouse attached to a dwelling; and it provided all the heating for both parts (passively from daytime solar inputs). The dwelling was unfinished with the walls unlined and uninsulated. The site was in a frost hollow; 750mm of coarse sandy loam; and 30% allophane in a waterlogged B horizon. Outdoors the temperature averages 12.8 degrees C in a year; minmum -4 at sunset in winter. Indoors it was in the 20s daytime winter, and above 10 degrees C minimum.
The answer to Ben\s question as to whether he's likely to get his ideal commercial quality fruit in a very simple greenhouse structure without any night heating: the short answer is yes, commercial quality bananas can be produced under plastic in a climate colder (outside) than where Ben is. However, there are the details to consider Ideally there should be a heat store. In its simplest form the passive greenhouse could be some poles leant against a building wall or an abandoned farm quarry at the right orientation having a polythene film stretched across the poles.

My conservatory was from the olden days. I have since moved and am now appreciating growing bananas outdoors in a “USDA zone 10b equivalent” climate with an average annual temperature of 15.7 degrees C.. Indoors at Inglewood Dwarf Cavendish grew to size (3m ) but never fruited. Outdoors here it' was extremely happy multiplying up and never fruited. Raja Puri outdoors tried its best to produced a stunted wisened bunch. The Australian Lady Finger types produce passable fruit unaided. That is: the fruit is of a quality that passes for commercial in New Zealand. To get them to develop and ripen properly I use bunch covers, in other words a little greenhouse around each bunch. This winter I have found augmenting that with bubble wrap brings the winter fruit quality up to where it should be: better than what I can buy. I have no plans to grow dwarfs, as my perception is that they are not practical to grow in my conditions as a staple food : taller cold tolerant or “subtropical”cultivars including FHIA-01 produce well easily and have dual purpose dessert and plantain use.

I am still considering the possibilities around growing banana plants under cover, even though the “consensus|” is for global warming, Gridshell structures provide the most strength for the least material and thus the least blocking of light to the crop. I also have a perception that fruit off plants grown in natural light tastes best. With this in mind I am looking at the idea of a retractable gridshell roof that could be used on an earth sheltered greenhouse. I am looking in the direction of something along the lines of that shown in:
PROTOCOL OF ERROR
The design and construction of a bending-active gridshell from natural bamboo
KRISTOF CROLLA and ADAM FINGRUT
http://papers.cumincad.org/data/work...ia2016_415.pdf

The retractable roof concept should be imagined from the example shown in:

Construction of mobile bamboo dome covered with textile canvas
Mario Augusto Seixas , José Luiz Mendes Ripper ,Khosrow Ghavami
https://umanitoba.ca/faculties/engin...ission_140.pdf

Re: bananas under plastic in cooler climates?
 

Funny to see this old post revived! The structure was almost like Shem suggested, essentially a semi-pit structure built into a hillside.

So results. Everything grew pretty well, I had early flowering on rajapuri and orinoco, and the cav. groupcv.s were getting close. Rajapuri choked even under plastic, but got ripe fruit from orinoco. I got fruit up to about half size on papaya and jakfruit too. Then in 2011 we had some bad weather and I got 30"of rain in 2 days with associated land slides etc. During the clean up a mob of cattle got into the structure and returned it to a pile of spare parts. As it was assembled out of eucalyptus poles thinned from my forest it was no great loss, but a shame I didn't quite prove my experiment either way.

My real job is organic farming, so part of the experiment was to see if I could produce organic bananas for local market. I used no fertiliser or sprays etc, just water and grass clippings for mulch. If if had continued I would look at soil fertility more seriously. I was amazed at how healthy the banana foliage was, that deep-green look that I remember from my time growing bananas commercially in the Australian subtropics. Considering mine were on very poor soil with only mulch I assume the heat made the difference.

Since that time I have not done much with bananas, as I have grown and planted about 250,000 forest trees and starting planting more easy-grow hardy fruit like avocados, cherimoyas, citrus tamarillo.

Some pictures;


Mahoi


General scene



Orinoco fruit, with the biggest commercial banana I could find in local shop for comparison

Re: bananas under plastic in cooler climates?
 

Interesting. Please tell me it's a very bad idea to raise a polytunnel on its face, bolt it to a sunny wall to grow my Ice Cream or Rajapurri (on their way to my home).

Re: bananas under plastic in cooler climates?
 

It's a very bad idea to raise a polytunnel on its face, bolt it to a sunny wall to grow your Ice Cream or Rajapurri (on their way to your home)..........
Unless:
the wall is insulated on the other side;
there is enough heat storage to prevent chill injury to the pseudostems & corms;
the tunnel has some form of double skin insulation, at least in winter;
the perimetre of the tunnel is insulated to at least a metre depth to prevent heat escaping through the soil;
the arch/support system is robust enough to stretch the plastic film taut/tight to prevent the plastic flapping in wind ( which might keep you awake) and prevent collapse from snow or hail load.
My thoughts are that if the wall involves a dwelling or storage building etc, then a quarter circle type tunnel would be better than a half round one because with the latter there could be opportunity for water to collect at the top of the wall and then penetrate the building.

Re: bananas under plastic in cooler climates?
 

Thanks a lot, Shem!

Re: bananas under plastic in cooler climates?
 

No one to refute my lack of judgement concerning fire risk?
If the wall is part of a building then it could still be a bad idea depending on the fire rating of the wall and the tunnel house plastic. I used twin walled polycarbonate sheeting that when burned gave of thick black smoke but self extinguished when the flame source was removed. EPFE is also alleged to be non-flammable. My understanding is that the rest of the transparent plastics are fuel.
Could someone update me on the options for transparent or translucent plastic that wont add to a fire?

Re: bananas under plastic in cooler climates?
 

man 2010 ? old post for sure but i will chime in and say I grow rajah puri under plastic in zone 7 north carolina usa with no heat and thay maintain thier leaves and even grow some even though we see temptures as low as 8 f some times I have one fruting now check the post in cold hardy bananas


http://www.bananas.org/f15/banana-sp...use-22664.html


january this year




now