Cohiba

I am about to attempt my first in-ground planting of a couple dwarf orinocos. The soil we have here has quite a lot of clay in it. I have 3-4 inches that I can work with before the amendments that I'll use will start to spill over onto a concrete patio.

What should I use and how should I go about using it so that my bananas can grow and be their healthiest?

Will my bananas be alright once the roots get into the clay where the drainage isn't as good?

Would mulching be a bad idea?

Thanks!,
BJ