Green onions

Green onions do not have one tidy place of origin because the name describes a culinary product, not a single species. In many markets they are young forms of the common bulb onion, Allium cepa, harvested before a large bulb develops. Elsewhere, especially in East Asian agriculture, similar bunching onions may be Allium fistulosum, commonly called Welsh onion despite its Asian origins.

The ancestry of the common onion is difficult to reconstruct because centuries of cultivation obscured its wild beginnings. Botanists generally place its domestication somewhere in Central or western Asia, where related wild alliums occur. Ancient societies across western Asia and the eastern Mediterranean cultivated onions early, valuing plants that stored well as well as fresh leaves eaten before bulb maturity.

Welsh onion followed a related but distinct path in Asia. It was cultivated for its hollow green leaves and elongated white stalk rather than a rounded bulb, becoming deeply established in Chinese, Japanese, and Korean cuisines. Repeated selection produced varieties suited to bunching, blanching and year-round harvest.

Today, “green onion,” “scallion,” and “bunching onion” often overlap in everyday speech. Commercial crops are grown widely, with China, Japan, South Korea and Mexico among important producers and California and Arizona supplying the United States. Their modern identity remains practical: tender onions pulled young, or nonbulbing onions bred to stay slender.