Blackberries on Deck
I'm practising some SFG in the yard...but I also have a very large deck, that takes up nearly 1/3 of my backyard. Additionally...this deck represents my sunniest area of the yard. So, I'm interested in utilizing some container gardening...and am already doing two potato towers on one end. What I'm interested in doing is creating a trellised blackberry wall on the west end of the deck. This will get the most sun, and ALSO..will hopefully act as a shade for our deck table (for evening meals). Currently, our evening meals are dominated by the strong setting sun, sitting too low for our table umbrella to block. My questions are:
A) I'd like to ultimately have a source of approximately 20-25 quarts of berries....how many plants will I need;
B) On a deck, is it feasible to create this trellis wall of berries...or is it better to go with the bush-style plant.
C) How deep should my container be, for these plants?
D) Would a Mel's mix be a good soil for blackberries?
Thanks in advance for anyone's insight!