Root vegetables make up a huge part of our diet. They are rich in carbohydrates, and so they’re a staple food in most cultures. Potato, sweet potato, carrot, turnip, ginger, and taro are all classic examples of root vegetables. But, are onions considered a root vegetable?
In culinary terms, onions are considered root vegetables, even though they aren’t technically a true root. In botanical terms, the round, fleshy part of an onion that we eat is actually a modified stem or tunicate bulb. Generally, root vegetables encompass any food plants that grow under the soil.
Onions are one of the most widely-eaten root vegetables on the planet because they are packed with flavor and nutrients. Let’s now discuss why onions are considered root vegetables, how they grow, and their benefits.
Why Is Onion Considered A Root Vegetable?
Food crops that grow under the soil are generally referred to as root vegetables.
When we think of root vegetables, the first ones that spring to mind are usually potato, carrot, beetroot, or sweet potato.
Why do onions seem different from these vegetables?
Onion is considered a root vegetable because it grows underneath the ground.
However, there are some key differences between “classic” root vegetables and onions.
Root Vegetables: True Roots vs. Non-Roots
From a botanical standpoint, there are two different types of root vegetables: true roots and non-roots.
- True roots refer to veggies that grow a long, thick taproot or have tuberous roots. For example, carrots or potatoes.
- Non-roots refer to veggies that grow from bulbs, corms, or rhizomes. For example, ginger or turmeric.
True roots and non-roots serve a similar purpose in plants: they are both types of storage organs.
All the glucose that a plant produces is stored as starch in these structures.
Plants keep starch and water stored underground to sustain them through winter or in times of drought.
When we use root vegetables in the kitchen, we hardly ever distinguish between true roots and non-roots.
But for interest’s sake, onions fall into the non-root category.
Onions Are Modified Stems
While we may call onions root vegetables, they aren’t actually roots.
The round, fleshy part of an onion that we eat is, in fact, a bulb or modified stem.
The onion’s roots grow out of the flat bottom of the onion (the basal plate).
The layers that make up an onion are fleshy scale leaves.
In the middle of the bulb is the plant’s growing tip.
When onions sprout green leaves, they grow out of the center of the onion.
Are Spring Onions Root Vegetables?
Like onions, the edible parts of spring onions are actually their modified stems.
Spring onions are considered a root vegetable because they are technically the same species as regular onions, just harvested younger.
However, in a culinary sense, spring onions can also be considered a leaf vegetable because you eat the green parts.
Are Green Onions Root Vegetables?
Green onions or scallions are the same as spring onions. They are modified stems.
But because they grow partially underground, they can be called root vegetables in a culinary sense.
They can also be considered a leafy vegetable.
How Do Onions Grow?
The onions we buy from the shop are onion plants in their dormant state.
They look very different when they are growing in the soil.
The pointy side of an onion is where the green foliage used to grow from, and the bearded side is where the roots grew from.
Baby onions grow straight upright, and at first, they just look like a narrow, green, tube-like leaf.
Initially, onions don’t have a round bulb at their base.
As onions grow more leaves from their base, the bottom of the plant becomes more and more rounded.
Eventually, one can see the stem start to swell right below the soil surface.
As the onion matures, thin, protective leaves, called tunics, grow on the outside of the bulb.
The tunics are what we peel off of an onion.
Once onions are big enough to harvest, their green foliage starts to turn yellow and dries out.
One has to lift the onion bulbs from the soil using a garden fork.
To store onions long-term, one has to cure them by spreading them out to dry and keeping them in a dark, cool place for 2 or 3 weeks.
If onions are kept in a cool, dark place, they can keep for up to 3 months!
How To Eat More Onions In Your Diet?
Onions are most beneficial to us when eaten raw, but there are loads of other ways to eat them.
Here are ways you can add some extra onion to your diet:
- Start all your soups, stews, and stocks by sautéing onions.
- Include sliced onions in stir-fries.
- Add finely chopped red onions to your guacamole.
- Eat a tasty salsa of onion, tomato, and fresh coriander.
- Enjoy a salad of chickpeas, finely diced onion, and peppers.
- Add some finely chopped onion to homemade salad dressings.
- Sprinkle sliced red onion on top of salads, burgers, tacos, and fajitas.
- Add sliced onion when making an omelet, quiche, or frittata.
Types Of Root Vegetables
There are loads of different root vegetables out there!
The ones we are familiar with (onion, potato, carrot, beetroot) are just a handful of all the different types.
The following plants are all root vegetables:
- Chinese artichoke,
- Chinese water chestnut,
- Jerusalem artichoke/sunchoke,
- Lotus root,
- Sweet potato,
- Tiger nut,
- Turnip, and
- Yam or ube.