Is an Onion A Vegetable?

Are onions considered vegetables or fruits? Is an onion a vegetable? The answer is quite complicated.

Grown throughout the world, especially in temperate regions, onions count among the world’s oldest and most cultivated crops. Though they are low in nutrients, they are widely used in a variety of dishes and are valued chiefly for their flavor in cooking. They can also be served solely as cooked vegetables.

But isn’t it interesting that while onions are a standard and regular part of most diets around the world, a majority of people are still often confused about how to classify them? Most queries revolve around if onions are vegetables, or fruits, or something else.

In this article, we would discuss why the humble onion is one and not the other, and why the conundrum exists in the first place. The truth is in here. In the end, you should be able to give a definitive answer (with reasons too!) when faced with the ‘is an onion a vegetable or fruit’ question.

Is an Onion A Vegetable?

Before too much info muddles things up, keep in mind that an onion closely fits the profile of a vegetable than a fruit. If you are forced to jump off the fence, fall on the side that says onion is a vegetable and you’d be more right than wrong.

With that out of the way, we can get down to the business of explaining why. To be fair though, the answer is a bit more complicated. Scientifically, when considering an onion’s morphology, just a small portion of all onion varieties is completely vegetable.

That said, getting some definitions out of the way is the best place to start untangling this interesting question.

What is a vegetable?

While there are several definitions of what vegetable is, what sticks out is this: vegetable is the parts of plants that are edible either raw or cooked. These include leaves, flowers, stems, bulbs, roots, and even seeds.

You must have noticed that the basic definition of vegetables excludes fruits even though fruits are edible and are a part of most plants. So an even simpler vegetable definition would be something like: a vegetable is any part of a plant that can be eaten apart from the fruit.

Another common them when it comes to defining vegetables is the link to cuisine and cultural applications. Most vegetables are typically eaten as part of the main meal to complement carbohydrates and other foods. This is unlike desserts or snacks that are eaten separately from the main course.

What is a fruit?

The ‘fruit vs. vegetable’ dichotomy also features prominently in any discussion on whether an onion is a vegetable or not. The most frequent question asked goes something like: is an onion a fruit or vegetable? This makes it imperative to understand what fruits are and how different they are from vegetables to contextualize the definition of onions.

Fruits are basically the seeds-bearing parts of a plant that are produced from the ovaries of flowers. Though they can be eaten raw like onions, fruits’ classification is limited to only how they are formed from plants.

Based other that simple definition of fruits, and considering that onions are not produced from flowers, it is safe to conclude that onions are not fruits?

Why Some People Say Onion is a Fruit

The most notable reason is linked to the means of reproduction. Onions, even with the absence of seeds, can reproduce onions asexually from other onions. And since like fruits, onions have a way of reproducing themselves, they must be fruits too.

But one of the most critical ingredients in classifying fruits, the presence of seeds, is absent in the onion bulbs that are used to grow new onions. So, scientifically, onions can’t be fruits because they have no seeds.

Are onions root vegetables?

The onion clarification conundrum isn’t limited to fruit vs. vegetable only. Root vegetables get thrown into the mix fairly frequently and you would understand why in a bit.

Root vegetables are defined as the edible parts of plants that grow underground. The term broadly refers to all true root plants like tuberous and taproots on one hand, and non-root plants such as corms, rhizomes, tubers, and bulbs on the other.

As root veggies, onions are classified under bulbs. Bulbous plants like onions are notable for being able to store all or most of the produced nutrients in the bulbs located under the ground.

So from the point of view of the gardener, you can see why it feels right to classify onions as root vegetables. That notwithstanding, onions cannot be classified as strict bulbs.

How to Grow Onions in Pots [Ultimate Guide For Beginners]

What to know about Onions as a Vegetable

Everything we’ve discussed onions so far was simply foundational in understanding the accurate classification of onions.

The onion is a plant species of the Allium genus found in the Amaryllidaceae plant family. It holds the distinctive characteristic of being able to asexually reproduce from its own bulb that contains no seeds. This is unlike most fruits and typical vegetables that are cultivated using seeds.

The typical onion plant features shortened stems (bulbs) found underground. These stems are surrounded by scale leaves that are relatively fleshy compared to regular leaves.

The bulbs store all the necessary nutrients required for the growth of new onion plants.

That said, onions do have seeds that are produced from the fertilization that occurs in their flowers. These seeds can be used to grow new onion plants. The onion seeds develop from the flowers once every two years.  To be clear, the onions flowers bloom just once every two years to produce seeds.

This throws up a crucial problem when trying to produce or grow new onions using the seeds. Because the seeds germinate from the flowers biennially, it would take at least 24 months to start growing fresh onions from seeds. Nobody is inclined to wait that long when it’s more practical to cultivate onions using the bulbs.

The key takeaways from all the above are as follows:

Because onion doesn’t grow from the flowers of the plants, it doesn’t match the definition of fruits

The whole onion plant can’t be called a vegetable because of the presence of the edible bulb underground

Conversely, while the term ‘bulb’ may feel perfect when trying to classify an onion, experts (especially nutritionists) disagree due to the edible leafy part above the ground.

Other Common Plants With Confused Classification

Several other plants are also mislabeled either as fruits or vegetables. For example, tomatoes and cucumbers are wrongly called vegetables by chefs and nutritionists. In the case of tomatoes, it even became enmeshed in legal wranglings over taxation issues. The Supreme Court eventually ruled that tomato is a vegetable.

But scientists, going by the definition of fruits, consider the tomato fruit. After all, it grows at the end of a flower and has seeds. And since cucumbers also develop via the ovaries of flowers and have seeds, they are in line with the classic definition of fruits.

Other fruits that get similar treatment include peppers, zucchini, beans, peas, and pumpkins. They are commonly (but wrongly according to scientists) called veggies.

Wrapping up

As long as you are not under any pressure to give an accurate classification, you can confidently lean towards a veggie when asked to classify an onion either as fruit or vegetable.

Going deeper, however, it can get very complex because onions feature some characteristics of bulbs, vegetables, and fruits. But while having some characteristics of fruits, the fact that they don’t grow from flowers and the bulbs contain no seeds. means they can’t be classified as fruits.

In the context of solely the fleshy edible part that is below the ground, the onion is a bulb. But since the leafy part above ground is also edible, it is a vegetable.