Shrink the lawn. Most turf grasses require at least an inch of water a week to stay green in summer. So think about how much lawn you really need. When the owner of the Santa Monica property shown on these pages expressed his desire for a patch of turf where he could enjoy weekend volleyball games and where friends' toddling children could play safely, Lopez let form follow function, sculpting out a generous swath of sprinkler-irrigated lawn, then surrounding it with groundcovers and ornamental plants better suited to the local hot, dry weather.
Plant for your climate and site conditions—living things thrive best where they feel most at home. That can mean researching and putting in species native to the area, or ones that thrive in similar climes. Lopez's designs mix resilient Southern California natives like agave and Dudleya edulis (both succulents) with plants from places where conditions are similar, including Mexico, the Mediterranean region, South Africa, Chile, Australia, and arid parts of New Zealand. Be mindful of how much sun and shade your yard receives—and the potential of any plant you choose to be invasive.
Address drainage issues early on. Before planting, test your soil by digging a hole, filling it with water, and seeing how long it takes for the water to percolate out. Clay-heavy soils that are slow to release moisture will suffocate plants. Soils that are sieves—overly sandy or hard and nutrient-poor ones, for example—fail to give plant roots a chance to drink up available water before it runs off or seeps out of their reach. Once you know what type of soil you've got, you have two choices: Try to find plants that like it the way it is, or amend it to improve the way it drains. Adding peat moss and aged compost will help beef up poor soil; incorporating sand along with compost will loosen clay soil and improve drainage.
Irrigate effectively. The most efficient systems are slow, steady, and targeted. Use soaker hoses or drip systems in flower beds and around groundcovers, trees, and shrubs—they can reduce water use by 20 to 50 percent. Put turf irrigation on a separate valve that hooks up to in-ground sprinkler heads or microsprayers with flow-controlled nozzles. Pay attention to how rapidly (or sluggishly) the water is being absorbed and adjust the emission rate accordingly. Be sure to add a moisture sensor to any automated system so it doesn't go off in the rain. If yours is a manual operation, install a simple rain gauge to determine how much rainfall has reached the ground in any given area; supplement just enough to meet plants' demands.
Mulch in moderation. A 2- to 3-inch layer of aged pine bark, hardwood mulch, shredded leaves, or pine needles helps retain moisture. It also helps hide irrigation lines and suppress thirsty weeds. But don't overdo it: Too much moisture at ground level encourages roots to form close to the surface rather than down deep, where they'll help plants survive dry spells.
Establish a regular maintenance schedule. Plants that are happy and well-fed—not pruned back to sticks, beset by insects, or overcrowded—demand less water. Including, over the long haul, less toil-induced sweat off your own brow.