How To Grow Spring Onions: Growth and Care Guide


After tomatoes, onions are the second most popular vegetables in the world. Spring onions, also called green onions, are widespread not only because of their flavor, but also because it is one of the easiest vegetables to cultivate. They can grow in a garden, in a pot, or even in a glass of water.

Since several ways exist to grow spring onions, choosing a method to raise your first (or next) crop depends on the amount you want to plant, the space available to grow, and your budget. You can even decide to plant using seeds or the roots of other spring onions to start growing your own delicious crop of these vegetables.

Can I Grow Spring Onions Where I Live?

Spring onions became a favorite vegetable ingredient in Asian cuisine for stir-fry dishes, salads, and soups. Its popularity spread across the world due mostly to its milder flavor compared to a regular onion, but also because they can grow in every season, in places with limited space, in less sunlight, and both outdoors and indoors.

  • Unlike other vegetables, spring onions do not need 12 hours of sunlight a day.
  • They flourish in environments with as little as 6 hours of sun per day.
  • With no need for large amounts of sunlight, they may grow year round, even in winter.
  • You would have to live near either the Arctic or Antarctic Circle to fall below 6 hours of sunlight a day.

Another plus, spring onions need small quantities of water and can even grow without soil. This guide describes many methods that are good reasons for cultivating this plant. All you really need is water, sunlight, seeding materials, and your attention. The rest is up to you on how to grow spring onions fresher than any you will find at a supermarket.

Sowing Spring Onions in a Garden

If you have a garden and space available to grow another crop like the spring onion, it is better if you plant seeds. The advantage of seeds is that you can select them from catalogs and ensure the type of onions you will harvest. This is the most expensive option since a pack of 1,000 seeds can cost around $8, but it is also the best option.

This method produces larger quantities of spring onions and allows you to regrow them for more than one season. However, be aware that spring onions growing from seeds take longer to ripen than growing them from the roots of other onions.

  • After getting your preferred seeds, you need to plan the space in your garden for your new addition.
  • Spring onions should be planted in straight rows, with a distance between rows of 16 inches.
  • This is especially important since they may compete for ingredients and sunlight if they grow too close together.

Once you have a plotted space, begin preparing the soil to sow the seeds. Use your hands to dig holes down the row of your garden, remembering to keep around 2 inches between the holes. Place the seeds into them, then cover the holes with a half-inch of soil to protect them from birds and other predators.

Here’s a helpful video with some tips for growing spring onions:

Sowing Spring Onions in a Pot

If you do not have a garden or enough space for spring onions to grow outdoors, they can be planted indoor with pots. You should place the pot close to a window or balcony so your plants get as much sunlight as they can during the day, preferably no less than six hours per day.

The spring onions’ bulb needs to have enough space to mature freely. Therefore, your pot must be at least 8 inches deep and 11 inches wide. (source)

You can plant them with seeds if the size of the pot allows you to adhere to the 2-inch distance between holes. All you need to do is fill a medium-sized pot with loose soil and use your hands to dig as many holes as you want and then put the seeds into them.

It is more common to grow this vegetable from seeds if you are looking for mass cultivation, but for a pot you can use a spring onion that still has roots left on it to regrow. You will need approximately a half inch of the bottom of the spring onion that includes roots.

In this case, put the bottom with roots in a container or a glass with less than an inch of water. After seeing some growth over a few days, you can plant it in a pot prepared with loose soil, and set the pot close to a window to make sure it receives at least 6 hours of daily sunlight.

In a Plastic Container

This method is one where spring onions shine as an extremely popular and tasty plant that requires a very low level of maintenance to grow.  You can begin growing spring onions inexpensively and easily with any large enough plastic container. In this case, all you need to start is a container at least 8 inches deep.

Begin by punching about 10 holes in the bottom of your plastic planter to provide for drainage. Fill it with loose soil and dig as many holes as you desire, then plant either seeds or the bottoms of other spring onions with roots in the holes.

Here’s a helpful video about growing spring onions in a container:

In a Glass of Water

Spring onions can also regrow without soil. You can put the bottom of one onion that still has roots in a container or a tall glass filled with water. In a few days you will notice it growing.

Keep in mind more roots equals better results. This method works best when using the bottoms of other spring onions that have as many roots as possible since the vegetable will not receive nutrients from soil and therefore reduces the roots’ lifespans.

Watering Spring Onions

As every vegetable does, spring onions need water. If they are in a garden outdoors, you can water them as soon as you realize the soil feels dry to the touch, but avoid
overwatering the seeds.

If your onions are growing in a pot, make sure they receive water once a week and check if the soil is dry to the touch once a day. 

Spring onions in a glass with water and no soil need the water changed when it is no longer clear. (source)

The Use of Fertilizer

If you are growing your spring onions in a garden and want the best onions possible, you can use one cup of nitrogen-based fertilizer per twenty feet of row every 2 to 3 weeks after planting. If you want to avoid a chemical-based fertilizer, you can ALSO use banana peels or eggshells as natural fertilizers.

The banana peel and eggshell methods may also be used as fertilizers on soil in a pot or plastic container. Be aware that they may attract the attention of pets, especially if you already add ground eggshells to pet food for extra protein and calcium. Remember to keep fertilized spring onions out of reach from your indoor animals.

When Are They Ready?

Spring onions should be ready to harvest when they reach 6 inches in height and half an inch in thickness. This growth might take at least two months after planting. You can also leave them to grow longer, but you will find the flavor milder.

If you notice they are ready to be harvested, you can pull it out carefully from the ground with your hands or you can dig them out. If you want to regrow them without starting the process all over, you can cut the green slender top off and leave the roots in the ground for your next crop.

How to Store Harvested Spring Onions

If you are not going to consume them all at the same time and they have already reached 6 inches in height, you can store them in the fridge inside a container with water for up to one week. If you are storing them outside of the fridge, always avoid storing them in plastic bags.

Use mesh bags instead so the air can circulate among them. Unfortunately, this vegetable does not last as long as a regular onion. Therefore, it is recommended to consume them within 4 to 5 days after harvesting them. Keep in mind that a healthy spring onion should have a solid and shiny white lower part and the stems should be completely green.

Robert Sampson

I'm Robert Sampson and I live in Colorado where I spend a lot of time in the backyard with my family either grilling, playing games and sports, or working on a project to make our backyard a better place to be.

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