Akula

There is a member who grew bananas in a pit in a marginal zone in order to keep them warm through the winter. Mostly dwarf varieties as I recall. Can't remember his name unfortunately. He was pretty successful however the pit/hole was designed with a rain/flooding solution.

I have also read of people planting the corns of some plants a bit deeper in the soil for some benefit (to provide extra protection against wind toppling/leaning?) but my understanding is that the extra depth was a few inches (maybe 6") deeper than normally recommended and it was with varieties that are not as susceptible to corm rot.

There is a lot of coral not too far below the surface in many areas around Miami which could make excavation difficult plus the water table is pretty high which would lead to the hole filling up with very every rain event so a pump or other solution would be necessary. Roots would get too wet and rot if in standing water.

Maybe plant so that the tall banana plants are on the east side of the shorter plants so as the sun moves west they don't block it?

Good luck!