Walking onions, also called Egyptian walking onions, tree onions, winter onions, and perennial onions, are very easy to grow. Unlike an ordinary onion plant, Allium proliferum will produce little bulbs at the top of the plant in the summer. The weight of these marble-sized bulbils will pull the stem down, enabling the bulbils to root and produce a new plant. Although walking onions seem to walk by producing new plants a few inches away, they are not invasive.
Walking onions are very hardy, perennial plants in the DC metro area. They also are “passalongs,” easy to give away to friends. I received mine from a fellow member of the Potomac Unit of the Herb Society of America. She snapped off a few bulbils from an enormous tub of walking onion plants. She said when her kids were young, they used to grow them along the fence and weave the stems in and out of the holes. The tub of plants came from her original set about 30 years ago!
Walking onions prefer full sun, organic matter, and well-drained soil. They grow to about 2 feet tall with hollow green stems. All parts are edible. If you cut the stems for cooking or salads, cut only a few stems at a time and don’t cut the ones that have bulbils. Stems can be eaten fresh in salad or cooked. You can cut the bulbils when they form in the summer and use them for cooking or pickling. In the fall, the entire plant can be dug up to harvest the underground bulbs. Simply divide and used some of the bulbs like you would with regular onions in the kitchen and re-plant the rest. Or leave the plant as is in the ground and the foliage will die back in the winter and come back in the spring.