By Sid Perkins
From San Francisco, at a meeting of the American Geophysical Union
In many arid regions, environmentally conscious gardeners who want to conserve water eschew lush lawns and instead grow indigenous drought-tolerant plants amid arrangements of ornamental rocks. Now, chemical analyses suggest that some such landscaping choices aren’t doing the environment any favors.
Landscaping with crushed rock is popular in Las Vegas and many other cities in the southwestern United States. After the plants in such tableaus are watered, evaporation of soil moisture sometimes creates colorful crusts of salts on the surface of the ground, says Stephanie A. Mrozek of the University of Nevada, Las Vegas.