By Molly Day
All the Dirt on Gardening
Egyptian walking onions, Allium cepa, are an easy to grow, delicious, kitchen ingredient as well as an eye-catching garden specimen. Onions are bi-annuals, meaning that they grow leaves the first year and flowers, sets, or fruit the second year.
Bulb onions have been used as food and medicine since 5000 BC. Like garlic, leeks, chives and scallions, they are members of the lily family.
No one knows why this particular onion is named Egyptian. Ancient Egyptians thought that the shape and concentric rings of onions meant they were holy and they were used as currency to pay the workers who built the pyramids. Many pharaohs were buried with onions and small onions were found in the eye sockets of King Ramses IV's mummy.
All onions we think of as bulb onions are called Allium cepa. This particular onion does not have a typical flower head but makes small onions on the top instead.
The stalks are 2 to 3 feet tall at maturity and the plants are hardy in zones 5 to 11. Wherever they are originally planted they establish a small colony and it is fairly easy to keep them going for years. They are harvested in late-summer or fall. They need sun but are not particular about soil.
The bulblets can be ordered from seed companies such as Territorial Seed (www.territorlseed.com) and come in a one-ounce package of 25 to 30 bulblets ($17 for an ounce that will last a lifetime). They prefer to ship them in September for fall planting.
The resulting onion bulbs in the ground are harvested late summer. The bulblets are planted 1 inch deep and 5 to 6 inches apart, leaving room for them to develop into a cluster of onions.
When the tops of Egyptian walking onions are young, they can be used like green onions.
When they mature, the onions in the ground can be harvested for kitchen use.
In addition, the plants set a cluster of smaller onions on the top. When that top becomes too heavy, the entire stalk falls over and the small, top bulbs set roots where they fall. The plants walk, making new plants wherever the tops land.
To prevent them from walking all over the garden, remove the bulblets from the top and use them in the kitchen, share them with friends, or replant them like seed.
The other names given to these marvels include tree onion, top onion, topset onion, top setting onion and winter onions.
The top set names refer to the second set of onions that form on the top of each stalk. Tree onion is because they grow a twisting stalk from the cluster of sets at the top. Then, another cluster of sets grows at the end of the second stalk making it look like a branching tree.
Their winter onion name comes from the fact that they survive temperatures as low as 40 below zero.
Besides all those common names, they uniquely have a few formal names. Allium cepa var. proliferum is because they are proliferous — a plant that produces new individuals by producing offshoots in unusual places. Proliferous plants make a shoot from an organ that is normally the last. Egyptian Walking Onions produce a cluster of topsets from a cluster of topsets, forming a multi-tiered plant.
Another of its names is Allium cepa var. bulbiferous refers to the fact that they produce bulbs. And, they are called Allium cepa var. viviparum because they are viviparous meaning they produce bulbils or new plants rather than seeds. Egyptian Walking Onions sets germinate while they are still attached to the parent plants. They grow leaves and roots before they even touch the ground.