These onions go by various names - walking, tree, Egyptian, topset and multiplying onions.
They are similar to a shallot in size and taste.
These are sold in sets of six medium sized bulbs ready for planting (any smaller bulbs included are a bonus!).
Individual bulbs are planted and will multiply to form a clump of 6-10 or more bulbs. These can be plucked off the outside of the clump and eaten when required. Leaves and the topset/bulbets that form can also be eaten.
These onions are perennial. Once planted they will continuouly regrow by planting the bulbs that have multiplied or the bulbets that form.
Have a look at our blog for more detail on growing and eating them.