Use mulch to keep the soil moist

Mulch benefits landscaping in many ways.
In addition to protecting the soil from sun and wind, it greatly reduces evaporation and helps to keep soil moist. That reduces the need for watering. Mulch slows the growth of weeds and makes flower and perennial beds more attractive. However, some kinds of mulch can make soil more acidic.

Green points

LEED for HomesLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify. : 2 points for a basic landscape design, which includes adding mulch or soil amendments (SS 2).
NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. /ICC-700: 3 points for improving the soil with organic amendments and mulch (504.3).

Learn more in the Green Building Encyclopedia

Landscape: Native Plants and Soil