Author: Photograph by Alex Farnum

Veering off the flat Napa Valley wine route in St. Helena toward Spring Mountain, I ascended a steep, winding road. White rose bushes accented the drive leading into the Newton Vineyard estate—560 mountaintop acres on Spring Mountain’s southern slope. Perched 500 feet above sea level, 12 tall Cyprus trees flank the entrance. Here was Napa’s best-kept secret, a rooftop English garden.