For years, Marleen Zwiers had a design crush on a modern home in her Menlo Park, California, neighborhood. Then one day, a friend called: “Your house is for sale!” That afternoon, Zwiers and her husband, Arthur van Hoff, put in an offer. The house, built in 2006, had the minimalist aesthetic Zwiers loved, but the backyard—which edged a creek—presented a challenge. The existing ho-hum lawn wasn’t working, but landscape architect Keith Willig didn’t want to mimic the creek area either. “There’s no way to duplicate a natural setting,” he says. Instead, he played it up through contrast. He used structural plants and extended the home’s architectural geometry into the yard, loosening up the design toward the perimeter. Now Zwiers’s crush extends to the yard, which changes with the seasons. “The succulent blooms come and go; the grasses get big seed plumes,” she says. “It feels like a work of art.”