Is Onion a Vegetable Or A Fruit?

Last Updated on August 5, 2021 by Grow with Bovees

Onions – Almost everyone uses at least some type of onion in their daily food recipes to enhance the flavour of food (despite the fact that for some of us, it isn’t particularly pleasant to cut onions!).

Apart from being a favorite of food lovers, an onion bulb also has a number of health benefits and brings lots of nutrients to the human body….more on that later in this article.

Interestingly, while onions seem to make a pretty regular appearance in most people’s diet, people are often confused on how to classify them.

Are onions fruits or vegetables?

Well, vegetables and fruits are usually classified according to their characteristics.

A fruit is a fruit when its characteristics fit the profile of a fruit, and the same goes for vegetables.

Let’s get this out of the way; an onion is definitely a vegetable because it fits the basic profile of a vegetable.

But, when investigated thoroughly, the answer is somewhat more interesting than simply the fact that it is a vegetable.

Well, that’s what The Bovees Research team discovered anyway, and they thought it might be of interest to you too…so read on if you really want to ‘know your onions!’

What Makes an Onion a Vegetable?

While vegetables and fruits alike come from the edible portions of plants, they actually derive from different areas of the plant.

Fruits are formed by the ovaries of the flowers on flowering plants and are basically the container for the seeds of the plant.

Seeds are how these plants reproduce (although some plants have more than one way of reproducing, but more on that later.)

Onion bulbs do not contain seeds therefore they are not a fruit. Therefore they must be a vegetable.

What Makes a Vegetable a Vegetable?

When it comes to physiological attributes, what is the definition of a vegetable (you might also ask, how does a vegetable reproduce? But that’s for a different article…)

True vegetables, as we said before, can come from all edible parts of the plant, but generally the plant parts they come from are; the leaves, stems, roots, and bulbs as opposed to the ‘seed holders’.

Examples of different types of vegetables include; potatoes (roots), kale and lettuce (leaves), lima beans (combination of stem and leaves), turnips (roots), and onions (bulbs).

Why Do People Mistake Onions as Fruits?

Some people mistakenly refer to onions as being in the fruit category, arguing that onion bulbs are able to produce more onion plants, as fruits can.

Their claim being that since onions have a means to reproduce themselves, they are fruits.

What they overlook is the fact that onion bulbs don’t contain any seeds and seeds are part of the official scientific classification of a fruit.

 Where Do Onion Seeds Come From?

Onion seeds develop from the flowers of the onion plant.

Onion plants can only bloom once every two years (biennially), making it more difficult to collect onion seeds for planting.

However, while onions can be grown from their seeds, they can also be grown from their bulbs.

The seeds the flowers produce are as a result of successful fertilization that happens in the flowers. Onions don’t grow from the flowers, but the seeds the flowers have.

Onion plants usually have shortened underground stems that are surrounded by fleshy scale leaves. They don’t contain seeds, which is a requirement for being a fruit.

The ability of onions to grow from their bulbs (that have no seeds) can be quite confusing.

Most vegetables usually reproduce via seeds contained in fruits, but not all do. Some vegetables are able to reproduce asexually.

Onions are some of the vegetables that can reproduce asexually. Plants use three main methods to reproduce asexually – tuber, bulb, and runners.

Bulb vegetables, like onions, are able to store food and feed the growth of new plants. This enables them to reproduce without the need for seeds.

 Are Onions Root Vegetables?

Onions fall under the category of bulbous plants that store their nutrients in a storage structure located underground throughout their life cycle.

So, if it grows underground it must be a root, right?

Well, while botanists distinguish true roots (e.g. tuberous roots) from non-roots (tubers, bulbs, rhizomes, etc.), the term “root vegetable” is often used to refer to all these in both culinary and agricultural settings.

It therefore seems okay to refer to onions as a “root vegetable”, if you’re a gardener or a chef.

 Commonly Mislabeled Vegetables and Fruits

One of the most contentious debates on whether a food was a fruit or a vegetable, involved tomatoes. The debate grew immensely in the late 1800s (before there was a perfect explanation on record!), when a case surrounding the tomato was brought before the U.S. Supreme Court.

The Port of New York was looking to start collecting taxes on tomatoes. If tomatoes were classified as vegetables, they would get the right to collect taxes on them, and wouldn’t collect any tax if they were classified as fruits.

The court examined the tomato and decided it was a vegetable. The reasoning behind it was that people commonly referred to tomatoes as vegetables.

But, while a tomato is legally a vegetable in the U.S., it’s not considered one scientifically speaking.

According to the classification of botanists, the tomato is a fruit and the scientific explanation for that is because it contains seeds. This has become widely accepted worldwide when it comes to the varieties of foods.

The cucumber is also one of the most commonly mislabeled foods. Some people think that the cucumber is a vegetable, with chefs and nutritionists often referring to the cucumber as a vegetable due to its culinary structure and profile.

However, botanists do not classify a cucumber as a vegetable, but as a fruit. The acknowledged characteristics of fruits, places the cucumber squarely in the fruit column.

Since cucumbers develop from the ovaries of a flowering plant, they are considered a fruit, plus they have a seed bearing structure to them.

Examples of other frequently mislabeled fruits include pumpkins, peppers, zucchini, okra, string beans, peas and olives (sometimes called a ‘stone fruit’).

Are Onions easy to grow?

While we’re on the subject of onions, now that we’ve established it’s a vegetable, we may as well touch on a couple of other onion factoids.

One of which is that they are quite easy (and very satisfying!) to grow.

Do I Need a Garden To Grow Onions?

Even if you don’t have an outside area of ground that you can set aside as a fruit or vegetable garden, you can still have a successful indoor onion garden without too much of a problem.

A couple of clay pots, some decent potting compost and some seeds is all you really need.

As well as being a staple food source, onions are also a very aesthetically pleasing herbaceous plant.

The tops have tall architecturally pleasing green leaves reaching up to 75 cms in height.

Onion blooms are made up of a striking globe of individual onion flowers in shades from white, through every shade of lilac, to rich, regal purples.

With a medium-sized pot you could grow a single central onion and surround it with a selection of lower growing herbs.

What Are the Health Benefits of Onions?

Apart from containing various vitamins and minerals such as; vitamin C, vitamin B6, potassium and folate, onions are also regarding by many as being beneficial in curing, or speeding up the process of fighting, colds and flu.

This is down to the fact that they absorb bacteria.

So if you start to feel the symptoms of a cold coming on then it is recommended that you cut an onion in half and sleep with it next to your bed so that it absorbs the bacteria from your breath/body thereby aiding your body’s immune system to fight the infection.

By the same token then, you should not leave a cut onion uncovered in the fridge or vegetable store as it will attract bacteria.

Summary About Onions

Onions as a plant species are classified under the Allium genus, in the Amaryllidaceae family. They are generally categorized under bulb vegetables as they are usually not eaten alone, but are combined with other vegetables to create a meal or cook food.

While most fruits and vegetables grow from seeds, onions can grow asexually from their bulbs to reproduce new onions.

Onions store their nutrients in their bulbs and can reproduce asexually. The nutrients stored in the bulb are adequate to enable reproduction.

Final Thoughts: Is Onion a Vegetable?

Yes. Onions simply do not meet the definition of fruit – they don’t grow from the flower part of the plant, and they don’t contain seeds. And with the fact that the whole plant is edible, we cannot really classify them as a bulb only, which means we can categorize onions as vegetables.

So, the next time anyone questions you; “are onions a vegetable?” or tries convincing you that onions are fruits, give them a light “bulb” moment as you shed some light into the topic.

If you are a keen gardener, there is the added bonus that it is relatively easy to grow healthy onions yourself!