Walking onions, also known as tree onions, Egyptian onions and top-setting onions, are a prolific and easy to grow perennial vegetable suitable for a wide range of climate zones (can be grown in United States Climate Zones Three to Nine). In fact, the biggest problem you are likely to have with walking onions is that they are so prolific you might have trouble controlling them! They are sometimes called topsetting onions because onion bulbs form at the top of the plant instead of at the base as with regular onion species. As the onion bulbs grow in size, however, they begin to weigh down the stalk, and eventually some of the bulbs may touch the ground and develop roots to form a new plant. Hence the name "walking onions" - and these plants may very well walk across your entire garden! (It is probably for this reason that their Latin name is Allium proliferum).Walking onions are probably easiest obtained from a fellow gardener (search the vegetable discussion forums if you don't have a neighbor or friend) although there are some garden supply houses that offer them for sale as well. They are very easy to grow (pretty much propagating on their own), but with the first bulbs you plant be sure to make sure you have adequate space for them to spread.
Traditionally walking onions were pickled in the fall for winter use, and this is still a wonderful way to use them. You can also, however, use them as a substitute for regular onions - although because of their small size it will take several walking onions to replace one regular sized bulb onion (but given their prolific habit, this shouldn't be a problem once they are well established).
Photo Courtesy of Dave's Garden on Wikipedia.
