Urban gardening mainly means growing edible vegetables in a town. This practice has been traditionally used for economic reasons (subsistence agriculture), but now it has also acquired educational, nutraceutical, therapeutic and social relevance. The educational aspect of urban gardening has been the subject of a proposal for the newly born Science Shop in Florence (Italy). In the spirit of action-research, in our project we first decided to involve all (or many) potentially interested people. This has brought into light the galaxy of different aspects related to urban gardening and allowed the establishing of promising research lines. We discovered that this is a multi-disciplinary subject that touches themes dealing with agriculture, botany, psychology, chemistry, city planning and politics. We examine here the various aspects of urban gardening in the towns of Florence and Prato, two very different urban environments despite their proximity.