The Egyptian Walking Onion, often called the Tree Onion or Topset Onion, is a perennial member of the Allium genus. Unlike standard bulb onions that are planted annually, this hardy variety returns each spring. Its distinctive growth habit and multiple edible parts make it a unique and low-maintenance addition to any garden.
Defining the Walking Onion
The Egyptian Walking Onion (Allium × proliferum) is a recognized hybrid believed to be a sterile cross between the common onion (Allium cepa) and the Welsh onion (Allium fistulosum). This perennial plant is exceptionally cold-hardy, often surviving harsh winters to emerge early in the spring.
The most defining feature is its production of clusters of small bulbs, known as bulbils or topsets, at the top of the main flower stalk. These bulbils appear where a typical onion would produce flowers and seeds, giving the plant its “topset” moniker. The plant also produces a small, multiplier-style bulb at its base in the ground, similar to a shallot. The leaves are hollow and green, resembling scallions, and can grow quite tall, reaching up to three feet in height.
The Unique “Walking” Growth Cycle
The plant earns its name from its self-propagating mechanism, which allows it to “walk” across the garden over time. As the summer progresses, the clusters of bulbils atop the stalk continue to grow, causing the stalk, or scape, to become top-heavy.
The increasing weight of the topsets eventually causes the tall, slender stalk to bend over toward the ground in a process called lodging. Once the bulbils make contact with the soil, they begin to root, establishing a new plant a short distance away from the original. This new plant will then grow its own stalk and topsets, continuing the cycle and effectively moving the plant approximately 12 to 24 inches each year. This method of vegetative reproduction sets the plant apart from all other common onion varieties.
Culinary Uses and Versatility
Every part of the Egyptian Walking Onion is edible, offering a range of flavors and textures throughout the growing season. The hollow, green leaves emerge early in the spring and can be harvested and used like chives or scallions. These greens offer a mild, fresh onion flavor and will regrow quickly after being clipped.
The aerial bulbils (topsets) are harvested in mid-to-late summer when they have reached their full size. These small, pungent onions have a sharper, spicier flavor than the greens and are often used whole for pickling or cooked into various dishes. Finally, the small bulb that forms underground can be harvested in the late summer or fall, providing a mild, sweet onion flavor that can be used in any recipe calling for a shallot or small onion.