Look into the idea of Urban Homesteading for your library and to educate your library patrons. It’s the idea that even in an urban setting you can be a bit of a farmer – from container gardening to having chickens – thus creating a better lifestyle for yourself and your family with local, in season, healthy and cheaper choices of food. California even has an Institute for Urban Homesteading who’s principals “preserve a slower, more intentional, more sustainable and more pleasurable way of life, rescue the lost arts of the garden, the kitchen and things done by hand and imbue everyday tasks with wonder and beauty.”
Perhaps a library could host local experts teaching workshops such as raising chickens in your backyard, beekeeping, canning, making yogurt, producing fruit and honey wines and cheese making.
Check out Fallen Fruit web site, which is attempting to map locations of public fruit in neighborhoods around the country(public fruit is fruit that overhangs sidewalks, parking lots, streets, etc.)