Growing Scallion, spring onion in a vertical garden

With a very small root system scallion is a choice specimen for a vertical garden.
Their upright greens are hollow, rounded and edible, as is their small white bulb,
similar to a mild and sweet garden onion. Full sun, moderate watering and a rich
medium will ensure strong and steady growth. Frost-hardy varieties will grow in
winter, others plant in spring through autumn.