Rooftop fruit tree containers

I'm in the process of building a rooftop garden with fruit trees (likely citrus, avocado, persimmon, kiwi, and maybe others) and want to ensure that the pots I use are big enough that the trees will fruit. The downside, though, is that I want to ensure that the pots have enough drainage and that they aren't too heavy so they can be moved if necessary.

Any suggestions for how I can make such pots and how to go about planting there? (I don't have access to a kiln.)

i would carefully check the weight tolerance of the roof first or if you have some sort of method of reinforcing, do so before planting.

I would think that you could build a 4x4x4 box of some sort to put your tree in, that should probably do it for most fruit trees, but I would also plant small size growers or dwarfs..best if you can find natural dwarfs..some plums are naturally dwarf. If you want to avoid spread you can try the pole varieties, they grow tall and narrow..remember dwarfs are not as strong and healthy as a standard tree, however, it is better than NO tree ..and if it is a rooftop and that is all you have..get the dwarfs, there are even superdwarfs that are avail for confined areas.

As that will require a lot of dirt, thus very heavy, you could put them on pallets if you have access to a pallet jack to move them around.