I noticed the depth of the beds toward the house were not as deep. I could do this on the hill side just above my fig and pear trees, like a terraced slope. Sure would take a lot of soil though. Does he say what he uses for soil?
He does have a video that addresses soil; I just haven't gotten to that one yet...he has another one where he rates seed catalogs, and I was proud to note that I have four of the five. :-)
He gave this catalog an 'honorable mention' for all the fans of fruit trees and shrubs...worth checking out.
He buys compost by the truck full.