There are many options for materials to build retaining walls in Phoenix Arizona. If you have a low budget, you may want to choose natural stone, which is relatively inexpensive. Of course, natural stone can crack and chip if used on a slope. Concrete and steel reinforced blocks are the second choice. Even though reinforced block walls are more costly than their cheaper counterparts, homeowners still choose them when building a retaining wall. It may be worth the extra expense if you want to build a Phoenix retaining wall that will last decades.