Passionfruit vines climb fences in the Fruitvale. Avocado trees drop fruit in backyards in San Leandro. Sapote — white and black varieties — has been showing up at a handful of plant sales and increasingly in the catalogs of nurseries like Planting Justice, a Richmond-based organization that has built one of the largest fruit tree inventories available for direct purchase in the region. Their list runs to dozens of varieties most people couldn't identify at a farmers market: pawpaw, loquat, feijoa, banana cultivars that will actually set fruit through a Bay Area summer.

The CRFG, which has operated local chapters in the Bay Area since the 1960s, hosts scion exchanges and fruit tastings that draw a specific kind of obsessive — the person who has been grafting trees in their backyard for twenty years and wants to talk about it. These aren't hidden in any official sense; the chapter meetings are public, the Planting Justice site is easy to find. What they are is off the radar of most people whose mental map of local food stops at the Ferry Building.

Someone walking through a residential block in the Dimond District or along the streets near Fruitvale BART tomorrow would see it if they slowed down: the unfamiliar leaf shape, the odd fruit, the neighbor who stops to explain what it is and offers to send you home with one.