I'm not exactly sure how a balcony garden is anyway camparable to vertical farming. Gardening on a balcony is little different than gardening in a backyard - pretty much only the venue is different. Vertical farming happens indoors, with artificial temperature and moisture control and artificial or natural light (or a combination of) and, to be any kind of replacement for traditional farming, needs to happen on an industrial scale. One particular problem with trying to grow some crops indoors is the need for pollination. Inside, there are no insects or winds to do that.
A couple of notes here, I essentially agree with the above, but will add some caveats below.
But on the subject of balcony growing.............as you might imagine, I have a few plants most years......
My balcony is 88ft2. I typically have about 88 plants (and still squeeze in room for 2 chairs and a table!) ....
I have been astounded at my growing season length this year.........it really is growing.
The tomatoes are long gone, but as of today (Nov 21st) my Portuguese Pepper plant is still growing peppers, albeit more slowly than in August.....
I assume tonight's frost may be its demise......but then again, I thought that a month ago.
I also still have harvestable (growing) Fresh Chives, Thyme, Rosemary and Mint.
Some combination of a more favourable climate and breeding to tolerate ever greater extremes would seem to be at work.
(Basil, Lettuces, Tomatoes and Corn are all long departed, but all made it well into October :O )
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On vertical farming...........you are quite correct that its most efficient for herbs and lettuces and the like........at this point.
But its worth saying, advances are coming along at a quick-pace.
I may discuss this more in a dedicated thread at some point.