To whom it may concern,
Although it may sound a bit unconventional, I chose to contact you
based
upon an article that was posted on your site detailing an experiment in
potted fruit trees. I have been searching for any kind of an authority
on
just this sort of information. My question is two-fold. But first a
summary
of what I am proposing. I wish to conduct a study of cash-crop fruit
trees
grown ( potted ) on the exterior face of a high-rise building. The
engineering alone is a challenge, but that is my personal concern. My
question to you is (1) How successful is the practice of potting fruit
trees, and what should I pay special attention to when designing the
potter
( i.e. depth and circumference of potter , drainage, and killing frost)
,
and (2) How high will Mason bees actively pollinate ( I am considering
testing this project on a building as high as 65 stories---800 ft ) of
coarse the hives could be positioned on different levels intermitenly,
but
if the bees cannot survive at such an altitude it would be to no avail.
Please respond as soon as possible. Also, in closing, if you have any
suggestions for any additional sources of information I would be very
appreciative.
Joshua Wilson

Joshua, I've had some experience with potted fruit trees, though it's been mostly a process of holding-them-over until I could find them a permeant home. From my personal experience with fruiting trees and plants, I'll add my thoughts on your project.

Up to 65 stories; that would definitely require a standard sized fruit tree of any variety! What's a Story - 10 to 12 feet? Let's say only 10 stories - 111 feet. I removed a standard "Banana Apple" tree that probably topped out at 40 feet; it was too high to prune, spray, or harvest (safely). I wonder, if pruned for height (something 'we' never do), if the trees vascular ability to 'pump sap' would reach 100 feet or more? And the amount of soil and roots necessary to support such a massive tree would have to be - massive. One big container; though I couldn't give you any specks.

I like this idea, but I wonder if a better candidate wouldn't be a fruiting vine? Climbing is their thing! I've read that one grape plant can be pruned to cover an entire acre; and I've got fuzzy kiwis that compete with them yearly!

I wonder what a Fig trees ability is? They really shoot up too, they love 'reflected heat,' and seem almost 'viney' in nature...

As far as pollination, that's a good question. (11 X 60 = 660 - feet) I live near 400 feet, my Uncle's at 700... His garden is always better than mine~ My suspicion: if you grew it - they would come! But then grapes are wind pollinated (I think?). Kiwi need male and female plants; but figs are self pollinating! (yet I don't know how? )

Structural supports and branch angle would be necessary for both upward growth and eventual fruiting. Neat idea - please keep us posted.

Dice,

In Chicago you probably get pretty cold winters and could have frost damage to roots in potted plants left outdoors all winter. If the pots are integral to the building some heat from the building would probably prevent winter-kill.

Ever hear of fruit drop? If Sir Isaac Newton walked under your 65 story building as an apple fell from a potted tree on the top floor, WOW, talk about discovering gravity! You had better stick to small fruits or berries.

Plants grown in pots need higher fertilizer requirements than those grown in soil because when they are watered there is a tendency for overwatering them and leaching away nutrients. The nutrients need continual replenishment. You'll need good drainage and probably need to design around frost breakage problems for the pots.

Could you contact me offlist? I think I can help, but I need more information than what you have on the forum. See my website for contact information.
-Lon J. Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com Winner of the Garden Writers Association "Best Talent in Writing" award for 2003.