The difference between spring onion, onion & leek
Learn how to distinguish the spring onion from the leek and the “normal” onion. The different characteristics are explained here.
The large genus of Allium encompasses numerous species of plants. Once several dozens of synonyms for one plant are included, it can all become a bit of a mess. In this article, we discuss the differences between some representatives of the Allium genus. Here are a few simple tricks that can help distinguish between the common onion, leek and spring onion.
Spring onion and its synonyms
The spring onion (Allium fistulosum) has a plethora of synonyms: Welsh onion, bunching onion, green onion and scallion. And these are just the most frequently used ones. But it is all one and the same plant. The key distinguishing feature of the spring onion is the long green to milky white body and hollow leaves. Moreover, the spring onion does not develop bulbs, unlike its other relatives. Some supermarkets sell spring onions that are supposed to form an actual onion bulb. However, the only plants from the Allium genus that have this ability are the common onions.
The common onion (Allium cepa) is easy to recognise. As mentioned above with the spring onions, only the common onions have the ability to form round, thickened bulbs. This ability has also won them their other name: the bulb onion. The green leaves of the common onion can be used for cooking just as well as spring onions and it makes hardly any difference in taste.
Leek (syn.: broadleaf wild leek, Allium ampeloprasum) also belongs to the genus Allium like the spring onion and the common onion. Just like the spring onion, the leek is not able to form an onion bulb. The lengthy body of the leek has a similar shape to that of the spring onion. The most obvious distinguishing feature of the leek, however, are the green leaves. While onions, whether they are normal onions or spring onions, always have tubular leaves, leeks have broad and flat leaves. Moreover, the leek tends to be bigger and thicker than the spring onion.