Are onions a fruit or vegetable? (How to classify onions)

In this article, we will answer the question “ Are onions a fruit or vegetable”? and discuss How to classify onions? 

Are onions a fruit or vegetable? 

An onion is a vegetable, not a fruit. An onion is a vegetable because vegetables do not have seeds inside them, while fruits have. Instead, the onion plant has seeds in its flowers which are found above ground. 

People often think onions are often fruit as onion bulbs can produce new onion plants asexually. 

What Makes an Onion a Vegetable?

Fruits and vegetables both come from plants, however, they develop from different parts of the plant. Fruits are developed from the ovaries of a flowering plant. They contain seeds and are used for further reproduction.

But, vegetables come from the edible portions of the plant. These edible parts of the plant include leaves, roots, stems, and bulbs. Examples of vegetables that come from these parts include: lettuce and kale (leaves), potatoes and turnips (roots), celery (stems), and onions (bulbs)

Onions belong to the plant genus known as Allium. Onions fall under the category of bulb vegetables. Onions are used in combination with other ingredients to make a meal. Onions increase the flavour of food.

Why Do People Think Onions are Fruits?

People often think an onion is a fruit because onion bulbs can use to produce more onions by the asexual method. As the onions reproduce by themselves, people mistakenly classify onions as fruits, although there are no seeds present in the onion bulb.

Where do onion seeds come from?

Onion seeds develop from the flower part of the onion plant. Onion plants only bloom once in two years, so collecting and planting onion seeds can be. This means it takes two years for seeds to produce. Onions are produced from their bulbs but can be grown from their seeds.

How to grow healthy onions?

How to grow healthy onions is a question most people ask when they have their garden that needs some extra attention. In the cold winter season, when the body usually lacks necessary vitamins, the immune system weakens, then as a result a susceptible individual suffers from cold-like symptoms. This issue can be resolved by planting more onions in a glass jar on the windowsill. 

Many people prefer plastic pots and believe that plastic containers are the ideal gardening tools since they are moveable and you can easily place them in the sun to make sure that your plants receive the adequate sunlight they require. 

Others even advocate putting potting soil in the bottom of the plastic container so that their plants don’t rot. However, you need to know how onions should be planted rather than how to grow onions in jars

There are two different ways you can plant onions in the open air: inside or outside the greenhouse. If you plant them indoors, to protect onion plants from too much heat the plants must be kept far enough away from windows.  

Uncovered windowsill is still a good location for an indoor onion garden. For mulching, you should put some peat or shredded coconut husk at the bottom of the windowsill. The mulch acts as protection for the roots as well as providing a source of nutrients for the green leaves.

For growing onions outdoors, the best option is to plant them in pots on the windowsill. Select the correct size pot based on the size of your greens. If using clay pots, you need to water them only when the soil is almost dry. You may consider using gravel for a smoother surface and creating a larger surface area for root growth.

Watering the onions is very important whether you grow onions outdoors or indoors. In the case of the clay pots, you should water them once a month and in the case of the plastic bottle, you should water them daily.

 The soil in the plastic container should be watered first followed by the watering of the onions. When the soil dries out, it should be re-watered before putting the tops of the containers in the sunlight. This will ensure proper growth of the roots. 

Other FAQs about Onions that you may be interested in.

How long do cooked onions last?

How long do diced onions last?

Can you eat an onion after it’s been cut?

Are there any other mislabeled fruits and vegetables?

One of the most controversial topics about whether a food was a fruit or vegetable involved the tomato. Tomato is legally a vegetable in the United States but scientifically it is not considered a vegetable. Botanists identified that the tomato is a fruit because it bears seeds. Today, most people accept the scientific explanation that a tomato is a fruit; though, some people still have doubts.

The cucumber is another food item people argue about whether it is a fruit or a vegetable. Some people think of the cucumber as a vegetable. Nutritionists and chefs often refer to the cucumber as a vegetable because of its culinary profile and structure. Cucumbers have rougher skin and can be used in the kitchen in stews and other savoury dishes.

A botanist would not define the cucumber as a vegetable but as a fruit. According to the physiological attributes of the plant, cucumbers are classified as fruit because they develop from the ovary of flowering plants.

Using the scientific classification of botanists, now it becomes very easy for people to identify fruits and vegetables. Some of these items will surprise you at first; however, it is easy to understand how they are fruits once you think about them.

 Some of the fruits mistakenly labelled as vegetables include peppers, pumpkins, olives (referred to as a stone fruit), okra, zucchini, and string beans.


In this article, we answered the question “ Are onions a fruit or vegetable?” and discussed How to classify onions. 


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Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.