I use containers to grow herbs, paprika, tomato, strawberries and such and i do grow elderberries, raspberries, black (aka Cassis), red and white currants, some herbs (
wood garlic, lemon balm, ...) and stingy
nettles under a walnut tree in shade (or in the shade of the house and a neighbours trees).
Almost everything under my wallnut tree grows there spontaneously from seed that either the birds or I dumped there.
I only have to knock back some exotics (pokeweed, false strawberry, bamboe, ....) that i don't want there.
In springtime most plant come up and by july most are in seed before the walnutt and the berrys dry the earth. So perhaps you might check what kind of usefull plants grow in spring. I harvest several greens and elderberry flowers in spring and early summer, then the berries, berrieleaves (for tisanes). Lemon balm, stingy nettles and raspberries i harvest till november.
The last months raspberries are not really tasty but they do well to make raspberry vinegar.
Hazel, some semiweld roses, prunes and blueberries are struggling for now. I expect to loose the blueberries. The soil is probably not acidic enough. Typically those are the only ones i actually bought and planted there. The blueberries BTW did well enough in containers. The hazel is also a spontaneous arrival. He is not in an ideal spot. Exactly on the border of my plot and that of my neighbour, in a too shady spot.
Off course i suppose this
experience is only usefull if your trees loose their folliage in winter
I'm not familiar with this zoning thing you use in the States. Where can i find some explanations ?