Use organic mulches such as chopped leaves, straw, grass clippings, compost, wood chips, shredded bark, sawdust, pine needles, and even paper around the base of plants to retain moisture. Initially you should water your plants deeply to allow the maximum amount of water to soak into the ground and then add mulch to prevent evaporation of the moisture as the sun heats the ground. Install a drip irrigation system to conserve water and provide adequate moisture.