Many of you probably know that Isabel Wade, Founding Executive Director of NPC, has been a leading advocate for trees and urban forestry, and was a founder of Friends of the Urban Forest. It shouldn't be a surprise that one of NPC's current initiatives is to advocate for the preservation and development of the trees within our city's parks, which are now facing a lack of attention and maintenance, in contrast to the attention being given to planting street trees. In the grand sweep of time, San Francisco's urban forest is a "relatively recent phenomenon," according to Mike Sullivan, Certified Arborist and author of The Trees of San Francisco. Sullivan points out that before the gold rush, "much of San Francisco was largely treeless, its grassy hills interrupted by only a few live oaks and California buckeyes huddled in wind sheltered valleys." Sullivan's book contains photo descriptions of 75 of the most common trees that that you'll find on the streets of San Francisco, and Sullivan's complementary website (www.sftrees.com) lists the locations of more than 200 spectacular landmark trees in the city.
San Francisco's Urban Forest
The introduction of The Trees of San Francisco informs us that during the early years of settlement in San Francisco, tree planting efforts focused on public parks, and also the creation of Golden Gate Park out of acres of sand dunes. Sullivan shares a choice quote from Frederick Law Olmsted, renowned landscape architect, who in 1865 warned that "there is not a full grown tree of beautiful proportions near San Francisco, nor have I seen any young trees that promised fairly, except, perhaps, of certain compact clump forms of evergreens, wholly wanting in grace and cheerfulness. It would not be wise nor safe to undertake to form a park upon any plan which assumed as a certainty that trees which would delight the eye can be made to grow near San Francisco." San Franciscan's love for trees persevered over Olmsted's concerns, and San Francisco's parks were planted with trees from all over the world. Sullivan points out that San Francisco's streets were relatively bare until as recently as the 1960s, and notes that "when Nikita Khrushchev visited the city in 1959, he commented on the city's beauty, but noted the remarkable lack of trees."
According to the San Francisco Urban Forestry Council, the urban forest in San Francisco has changed dramatically since then, and our city is now home to approximately 700,000 trees, with a minority population of these trees located in the city parks. Nonetheless, San Francisco still lags behind other communities: Friends of the Urban Forest estimates that the city has only 75 street trees per mile, compared to the national average of 120 trees per mile. That means that San Francisco has a little more than half the number of street trees of similarly-sized cities. Also, the condition of trees in San Francisco's parks are in decline; it is disappointing to report that the Recreation and Park Department does not include park trees in their inventory of "assets". The most recent assessment of city park trees was done back in the early 1990s.
Most Popular Trees in San Francisco
The top three tree species in the city's parks are Monterey Cypress (native to California), Monterey Pine (native to California), and Blue Gum Eucalyptus (native to Australia). According to Sullivan, the most popular street trees in San Francisco are the Purple Leaf Plum (cultivar of Cherry Plum, native to Asia Minor), the Japanese Flowering Cherry (native to Japan), and the New Zealand Christmas tree (native to New Zealand).
Sullivan does a great job of introducing the reader to some of the unique aspects of the urban forest in San Francisco. Sullivan's book features neighborhood walking tours (the Castro, Cole Valley, the Mission, Pacific Heights, Potrero Hill, the Financial District and Parnassus Heights) that guide you to interesting trees in San Francisco's diverse neighborhoods. His book is available for purchase here.
