From Patrick Gabridge:
When we re-landscaped the tiny bit of ground in front of our condo building, a volunteer tomato plant sprouted, probably from a castaway seed from some passerby's sandwich. This tomato grew in a small crack between the sidewalk and our cobblestones. Over the summer, neighbors cared for it, and it grew large enough to produce tomatoes for anyone to take (and they did). It also helped form the seed of an idea for a different kind of garden.