There are many options for materials to build retaining walls in Phoenix Arizona. Natural stone is a good option for those with a limited budget. Natural stone can crack or chip if it is 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. The extra cost may be worth it, though, especially if your goal is to build a retaining wall in Phoenix that will last for decades.