Because pear trees take five years or more to come into bearing, growers historically have not been very adventurous in planting new varieties, and so the Warren, with its unofficial provenance, has never made a big splash commercially. Pollination is tricky. Frog Hollow Farm's Courchesne — who has 9 acres of Warren and half an acre of Magness pears, planted from 1994 to 2003 — has to use a special blower to apply pollen to his flowers to get a decent crop.
But he loves the Warren. "It's got smooth, grit-free texture and an intense, complex flavor, with hints of guava, pineapple and honey," he says. After taking their own sweet time coming into bearing, his trees produced a bumper crop this year, and so he looked beyond his usual domains at the San Francisco Ferry Plaza and Berkeley farmers markets, to establish a beachhead in Southern California.