Try a piece of shade cloth draped from the wall out over the trees. This will shade both the trees and the wall from that blazing hot, dry sun. You may need to leave the shade cloth on for the whole summer, so you don't cook the plants. Make it as inconspicuous as possible? Or maybe get one of those shade cloth "sails" and set it up on some poles so it looks nice but still shades the plants.
Those plants will establish if you help them out but I'm definitely thinking it's too darn dry and sunny for them there, right now. When you water, spray the leaves as well as the soil around the plant, too.
I always use soluble Quick Start fertilizer when I plant new plants. It is supposed to stimulate the plant to make new roots and this of course will help it get established quicker.
