California is renowned for its diverse array of trees, including some of the largest and most iconic species on the planet. Among these giants are the native California redwood (Sequoia sempervirens) and the giant sequoia (Sequoiadendron giganteum), which proudly boast records for their sheer size and grandeur. However, in the bustling urban landscape of San Francisco, where microclimates, windy conditions, and unique soil compositions prevail, the native tree canopy tells a different story, albeit one equally rich in history and ecological significance.
Before the widespread tree plantings of the late 1800s, San Francisco was already home to pockets of native trees, nestled near creeks, in canyons, and on the city’s less windy eastern side. These early residents included native oaks, bay laurels, willows, and the California buckeye, each playing a vital role in the local ecosystem. The coast live oak, in particular, held significant cultural importance as a food source for the indigenous Ohlone Indians, who utilized its acorns for sustenance throughout the year.
Despite urbanization and the introduction of non-native species, a handful of native trees and shrubs have persisted in San Francisco’s landscape, serving as reminders of the city’s ecological heritage. Among these resilient natives are the California buckeye (Aesculus californica) and the hollyleaf cherry (Prunus ilicifolia), each contributing unique characteristics to the urban environment.
The California buckeye, affectionately known as the “tree for all seasons,” offers a striking display throughout the year. In spring, its vibrant chartreuse foliage heralds the arrival of warmer days, followed by cone-like white flower spikes that adorn its branches. In fall and winter, the tree sheds its leaves and fruit, leaving behind silvery bare branches that shimmer in the moonlight. Despite its toxic seeds, which were historically used by indigenous tribes for fishing and fire-making, the California buckeye remains a favorite among native bees, hummingbirds, and butterflies for its sweetly fragrant flowers.
Similarly, the hollyleaf cherry, or Islais cherry, adds a touch of evergreen charm to San Francisco’s landscape. With its shiny, spiny-toothed leaves and sweet edible cherries, this native shrub/tree attracts a myriad of wildlife, from bees and birds to small mammals. Despite its minimal flesh, the cherry’s seeds were prized by native tribes for their culinary and medicinal uses, highlighting the plant’s multifaceted significance in indigenous cultures.
Both the California buckeye and the hollyleaf cherry thrive in San Francisco’s climate, requiring minimal care and water while providing essential habitat for local wildlife. These native trees and shrubs serve as living links to the city’s ecological past, reminding residents of the importance of preserving and celebrating San Francisco’s natural heritage.
As urban landscapes continue to evolve, embracing and promoting native trees like the California buckeye and hollyleaf cherry can help foster biodiversity, support pollinators, and enhance the resilience of our cities in the face of climate change. By recognizing the value of these long-time residents, we can ensure that San Francisco remains a vibrant and ecologically rich environment for generations to come.