I live in a high desert area and have those monumental temperature swings as well. A sunken
greenhouse or modified sunken
greenhouse has served me well. One of my greenhouses I constructed beds slightly over three foot tall and three foot wide i placed bales of
straw in the base of the beds and then good soil on top of the bales. Essentially using the beds as if they had a walk way dug below grade. We incorporated other trial experiments but I think the mass of the beds or sinking the beds was the most effective part of that particular greenhouse.