‘A leftover dahlia that came with their new San Francisco home is what hooked Gerda Juul and her husband, Erik, in the 1950s.

“It sort of went on from there,” she recalled, to buying bulbs at the Dahlia Society of California’s annual sales, to a membership (free with the purchase of a dozen bulbs). “Then, about 35 years ago, after we moved to the Sunset, we seriously started to grow and show and hybridize.”

The dahlia mystique goes back to pre-Conquest Mexico, where the Aztecs cultivated them. Today, it’s Mexico’s national flower. It’s also the official flower of San Francisco – Mayor Gavin Newsom has declared Saturday to be Dahlia Flower Day.

A Spanish botanist, Vicente de Cervantes, sent the seeds of several natural species to Madrid in 1789; seeds collected by the explorer Alexander von Humboldt reached Paris and Berlin in 1804. Those founding seeds gave rise to a multitude of hybrids. The American Dahlia Society recognizes 18 form categories, based on the shape of the flower head (ball, pompon, stellar) or its resemblance to other kinds of flowers (anemone, cactus, water lily, peony, orchid). There’s also a flower-size hierarchy, from AA on down. The group’s annual show, this weekend at the County Fair Building in Golden Gate Park, puts ever more people in danger of dahlia addiction  .  .  .

Beyond their home garden, the Juuls helped maintain the Dahlia Dell in Golden Gate Park for 15 years  .  .  .  Other volunteers help tend the dell, with the park providing space, soil and rototilling.’

Don’t miss seeing these spectacular flowers growing in the park this month!

via Hello, dahlia! S.F.’s official flower in bloom.