Recent drought coupled with population growth throughout the southwestern United States have increased the demand for water efficient alternatives in landscaping projects. As a result, xeriscaping has become a popular form of landscaping. Currently, there are no regulations controlling the mineralogy of the decorative rocks that can be used for these purposes. In this study, we examined two public high schools and one city park in Las Vegas, NV, where green and white salt efflorescence was observed on recently emplaced decorative rocks used as ground cover. The landscaping rocks, underlying soil, surface salt crusts, irrigation water runoff, and plants were analyzed to determine their mineralogy and chemistry. Pyrite and high levels of copper were found in the decorative rock. Acid-rock drainage caused by the oxidation of pyrite has concentrated copper in Mg-sulfate salt crusts, and As, Cu, Mo, Pb, and Cr in plant tissues. These metals are not known to occur naturally in the soils of the Las Vegas Valley, and our results indicate that their source is the landscaping aggregate. The high solubility of the metal-containing salt crusts increases the potential for surface and aquifer contamination. The continued use of these products, especially as cover for school grounds and park recreation areas, should be stopped because of the increased potential for exposure of children to heavy metals. In addition, the increased costs associated with possible plant mortality, and increased sulfate salt production is not desirable. Regulations should be developed to prevent the use of rocks containing sulfides in future landscaping applications.