Tree onion, also known as Egyptian onion, top onion, walking onion, or perennial onion, is a type of onion that can grow indefinitely and produces new onion bulbs at the top of its stem. This onion variety is easy to grow, and leaves a unique flavor in cooking due to its green stems and small bulbs. For those in search of a different name to refer to this type of onion, tree onion synonyms include winter onion, winter leek, summer onion, everlasting onion, potato onion, and multiplier onion. Whatever you choose to call it, this onion variety is a versatile, low-maintenance addition to any garden or kitchen.