I am making a new patio off the south wall of my Southern Calilfornia home, with a 6' high stucco wall on the southern edge of the patio. I want to extend a hedge above the wall for privacy. My plan is to prune the trunks until they reach the top of the wall and then keep the hedge pruned to 2' high above it. I am thinking of dwarf citrus, or camellias, or something more than just green leaves. But I will need something that will not be wider than 2' after pruning. I will also want straight trunks. Thank you for your suggestions. ... I just discovered this is called pleaching. Lots to learn!