Sidewalk bitter melons in two buckets and plastic twine

I first saw these vines a month ago on a nearby sidewalk. They are growing in plastic buckets with an elaborate plastic twine trellis supported by a tree branch. Initially I misidentified them as morning glory. Recently, I saw how tall and thick the vines had become, and that they are in fact bitter melon, with vegetables ready to eat. The shop owner saw me taking these photos, and seemed very proud of his summer edible garden on a busy street.