Calcot onions are available mid-fall to early winter. Current Facts The Calcot onion is a type of green onion known as blanca gran tardana in the Catalan language from Lleida, Catalonia, Spain. As with many agricultural products, the Calcot onion from Tarragona, Catalonia is a registered EU Protected Geographical Indication.
The potato onion (also known as multiplier onion) is a variety of the Aggregatum Group of Allium cepa, similar to the shallot, although producing larger bulbs. It is remarkably easy to grow, keeps better than almost any other variety of onion, and is ideal for the home gardener with restricted space. It was very popular in the past, but--like many old varieties--it has been passed over in favor of types more suitable for mechanical harvesting and mass marketing.