Hey Kim I have a little cabin near you, near Joshua Tree. I talk to locals about what does well up here. My neighbors say that a lot of things grow fine up here with water of course!!! First thing you have to do is plant some trees so they can provide shade for smaller plants. I love native trees like the honey mesquite and palo verde trees. Dont get the chilean mesquites they sell at home depot or other nurseries. I know a guy in Joshua Tree that sells them his name is Damian Lester. His email is email@example.com
My neighbor has a bunch of Afghan pine trees also called Eldarica Pine or Mondell pine. They do great up in the high desert. I planted one last year and it grew 2 feet!! I only water it once a month (deep watering). Have you been to Cactus Mart? They have a lot of cool desert trees its in Morongo Valley.