We are sitting on top of at least 6 feet (that is as deep as I've dug) of heavy thick clay that is very poor draining.

I'm thinking of utilizing shallow raised circular planting beds (perhaps 6-8" above grade) to give my figs a fighting chance to get their roots punched into the clay and established and not drown in the interim.

Excavate a shallow, gently sloping "bowl", and install a retaining ring about 8" above grade. Mix in my amendments and additional native soil, to back-fill the hole to and set the transplant in the new bed.

Then after a year or three, I can remove the frames and let the mound edges collapse and feather back out into the surrounding yard, thus creating a gentle crown to the center.... That is the plan, anyways.

Secondly, spacing:

I was intending to plant the figs along a southern facing wall. I figured(pun intended) that to set them in a row, 5 feet away from the building and 10 feet from each other would give me enough room (with careful pruning)to develop each of the 4 plants into a 6 foot globe, and they would not compete with each other for light or air. (And provide some much needed shade to said wall and hopefully cut down on our cooling bill slightly !!)

What say those in the know to my battle plan?