This TED talk is a really great story of just making it happen. A small town in England decides that it will convert its landscape into an edible landscape. And why not? Why should there be a stigma against an apple tree on the sidewalk? The energy we expend towards ornamentals can easily be put into edibles, and be as pretty as well. A nasturtium is a tasty leaf and flower. The environmentalist David Orr is doing something similar in Oberlin, Ohio. The city is supporting the development of new area farms, with the goal of locally producing 70% of the food the city eats (I think that 70% is a good number, what would life be without olive oil, wine, Parmesan, and citrus after all?).
This is an additional level of complexity for students to organize growing space in buildings and landscapes. Ultimately it is spatial – requiring thinking about the massing and space the plants make, but also what they need to grow and thrive.