There are over one hundred Urban Gardens in San Francisco, many of which have open plots or regularly solicit help from volunteers - you don’t necessarily have to start your own garden in order to practice urban agriculture. If you are willing to do a little research, there is always a way to get involved! The two main ways San Franciscans participate in urban agriculture include starting your own garden or participating in an existing garden.
You can find detailed information on how to launch any of these projects at the San Francisco Urban Agriculture Alliance (SFUAA) resources page or on this City and County of San Francisco Urban Agriculture Program.
The City and County of San Francisco’s Recreation and Park Department is a great resource for urban gardening. The Recreation and Park Department supports and manages a program of 43 community gardens (and growing!) on City-owned property, where members can grow produce and ornamental plants for personal use. Gardens range in size from a few hundred square feet to thousands of square feet; some offer individual plots while others have shared plots. Some gardens also offer demonstration gardening or other instructional programming. The Community Gardens Program is a substantial component of the new citywide Urban Agriculture Program.