In this town, there are blocks and blocks of homes without any greenery.
The streets that traverse the well-kept Marina district, for example, sport modern city housing but no shrubs, no front lawns, no visible flower beds, and no trees.
But now, these and other neighborhood streets will get a chance to change this edifice-to-concrete-curb look with trees. Three of the city's residential areas will get sidewalk trees planted - and all for free.
Friends of the Urban Forest, a nonprofit San Francisco organization devoted to the planting and preservation of trees, is sponsoring a citywide Treescape Competition which ends next Wednesday. Neighborhood groups are presenting plans to add at least 50 trees to their streets or public spaces.
The first-place winner will be awarded 250 trees plus the materials to plant and sustain them.
This latter assistance - valued commercially at $50,000 - will include arranging for city permits, sidewalk cutting, hole-digging, the purchase of stakes and ties, and, of course, delivery of the trees.
Second and third places are 75 and 50 trees, respectively, along with planting assistance.
Although visitors wandering today through the eucalyptus forests of the Presidio and the wooded grandeur of Golden Gate Park find it hard to believe, San Francisco as a city was originally devoid of much greenery.
Old-timers say the Presidio even as late as the 1900s was partly a wind-swept desert of scrubby brush and flying sand. The lovely open groves of today were subsequently planted, just as were those of Golden Gate Park, many small block-square parks within the city, and most of Mt. Davidson.
The Friends of the Urban Forest competition is aimed at enhancing neighborhood identities.
''The city's planning code now specifies that sidewalk trees must be included in the site plan where there is new construction,'' said Ruth Gravanis, executive director of FUF.
''What we hope to do is develop tree-planting interest in some of the older areas,'' she says. ''We want groups to come up with progressive landscaping ideas for their sidewalks and public areas.''
During the competition, she adds, architectural students from the University of California, Berkeley, are available for consultations, as is the local FUF staff.
Ms. Gravanis points out that the varied area climates of the city will probably produce requests for a wide range of tree specimens. Most sidewalk trees being planted today include sycamore, maytem, Victoria box, Australian willow, magnolia, privet, flowering plum, and eucalyptus. Very few conifers are used because of their shallow root systems.
FUF's tax-exempt activities are supported by grants from the National Endowment for the Arts, private contributions, and service charges for certain tree-planting projects. Since its inception last year, Friends of the Urban Forest has assisted the city's neighborhood groups in planting more than 850 trees.
''We believe trees are essential to urban life,'' Ms. Gravanis asserts. She points out that trees can do everything from blocking winds or lessening heat loss from buildings to attracting shoppers to commercial areas or raising residential property values without raising assessments.
Further, trees increase neighborhood pride while enhancing the livability of urban environments.