Heirloom and Rare Onion Varieties

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Tree Onions UK

This unusual and almost forgotten onion gets its name from the curious onion bulbs or "sets" that form on its flower stalk and grow into miniature onions with a tree-like structure.

Tree Onion - Catawissa - 2 Months Growth
Here's a Catawissa Tree Onion grown from bulbil in the UK
After just 2 months growth, new bulbils are just starting to emerge
Catawissa Onion Head - Miniature Bulbils
Once the paper thin skin folds back, the bulbils (bulblets) with their own growth can be clearly seen in this UK grown Catawissa onion flower head.
The mini bulbs spray out horizontally while the young flowers are roughly upright from the centre
Tree Onion Flowes and Shooting Onion Bulbs
The tree onion bulbs continue to develop and are already showing considerable growth of green shoots but they're not walking yet

Top Onions, Top Setting or Top Set Onions

A traditional name for immature onions that you can plant instead of starting from seed is a "set". Hence, another, long established, and common name for tree onions derives from these "sets" or tiny onions that grow on the top of the onion flower stalk. Not surprisingly, they can be found as "top set" or "top setting" onions

Egyptian Onions or Egyptian Walking Onions

Many of the old seed and plant catalogues can refer to tree onions as "Egyptian onions", presumably for the notion that these onions originated in Egypt but more likely a corruption of "gypsy" and the introduction of these plants to some areas by travellers.

Egyptian "walking" onion seems to be a comparatively recent name extension referring to the curious way these plants propagate. The onion sets make the plant top heavy, so the stalk begins to bend under its own weight and eventually touches the ground. The cluster of miniature onions then starts to root and grow into the ground to establish a new group of plants. In this way, season by season, these onions "walk" and self propagate

Tree Onions in the UK

One of the earliest direct references to tree onions in the UK comes from "The English Flora" published in 1775 and illustrated below. The generally accepted view is that they were introduced from Canada in 1820 which seems quite late considering it was known at least 45 years earlier. "Curtis's Botanical Magazine" of 1812 clearly illustrates the tree onion and even suggests that it is often mistaken for Allium canadense

The earliest published reference is attributed to the "Historia Generalis Plantarum" of 1586 by Jacques Daléchamps

Tree Onion Allium cepa proliferum
One of the earliest references to tree onion (1775) (Allium cepa arborea)
Modern Onion Production - Plant and Repeat

Modern agriculture has lead to the production and use of convenient onion varieties that are easy to grow from seed , harvest, store and transport. But, they are almost always grown as annuals and need fresh onion seeds or sets planted every year.

Perennial Onions - Ideal for Allotments, Potager's or Cottage Gardens
The perennial onion varieties can last for many years, are easy to grow and winter hardy. New plants have to be propagated from bulbs produced as either a top "set" or from the onion growing and dividing into 2 or more bulbs. If left, they can pretty much take care of themselves

A Source of Onions Nearly All Year Long
The tree onion is Winter hardy, prolific and produces plenty of green onion growth for salad and culinary use while the small bulbs can be pickled or used as regular onions. You don't have to keep buying "sets" or seed but can simply plant once and divide or tidy your onion bed now and again

Multiplier Onion - Tree Onions Divide

One of the great things about tree onions is that they have the ability to "split" into multiple onions. From one onion you can easily get 2 or more bulbs by the next growing season as the bulb divides, sometimes several times to form a cluster

Tree Onion - Multiplier Onion
Tree onions can "multiply" over a season to increase your stock for the next season - One onion can become 2 or 3 or 5...