You live in USDA Zone 8, which is definitely warm, but there are lots of plants you can grow there. BHG.com has Plan-A-Garden, which would help you to site rock walls on your property without hauling them first. A dry stacked wall would probably be your best bet. Just start stacking and fitting! You could also use some of those rocks within a rock garden. Plant roots stay moist when they are beneath rocks. You may have to bring in topsoil to give yourself more dirt to work with.