How to Grow Green Onions in Water from Your Food Waste

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How to regrow green onions in soil

If you want continuous harvests over a long period

If you want continuous harvests over a long period of time, growing green onions in soil is the way to go. After trimming the scallions (in Step 2 above) plant them in a garden bed or a pot filled with good quality soil.

You can also add some organic fertilizer especially when using a small pot. The top tip of each stem should be above soil. Keep the plants in full sun or at least half day sun, and water regularly.

Use a stick or pencil to poke holes in the soil, a

Use a stick or pencil to poke holes in the soil, and place the green onion cuttings in the soil.

Many people assume that if a plant grows in water, then soggy soil must be ok. The answer is no. 

Soggy soil can breed bacteria, and cause root rot.

Soggy soil can breed bacteria, and cause root rot. So the most important thing to remember is to never let the soil get too dry, or too soggy by sitting in a tray of water for more than a day.

Green onion scraps planted in soil can grow to huge sizes and give lots of harvests. They keep growing back as you cut them. If you protect them from snow and frost, they will keep growing!

Are green onions the same as scallions?

This will be yours- but without the store.
This will be yours- but without the store.

Yes, they’re the same thing.

You may find them called either or and there’s no need to get confused over it. Regrowing scallions is the same as regrowing green onions.

Green onions may also be called spring onions. But they’re all referring to the same plant- allium. This genus also includes other plants like like regular onion, leeks, shallots, and chives.

Similar to green onions, you can also regrow bok choy, fennel, and garlic.

Did you know you can regrow these plants as well? Isn’t that cool?

So, can you replant green onions or not?

You sure can! I’m honestly surprised at friends who eat green onions regularly but never consider growing it themselves. It’s so easy even a caveman can do it.

Once you set up the vessel you plan to grow it in, it takes care of itself. All it needs is a few water top-offs and that’s about it.

If you grow it in your garden, it makes an excellent addition to your garden edibles. It’s also super cheap to propagate and maintain because it basically requires minimal TLC.

Once you start, you’ll be dumbfounded and ask yourself why you didn’t do this sooner.

Planting the green onions to regrow in soil

While not completely necessary for everyone, I prefer to replant my green onions in the soil after about 1 week (or when they’re about 5 inches tall) so that the plant can get more nutrients from the soil. I found that leaving them in water to continue to grow will absolutely grow long shoots, but these shoots end up being thinner than green onions replanted in soil. 

As an added benefit to replanting green onions in soil, you can also grow green onion scapes! I was pleasantly surprised to find that scapes were growing in my green onion containers after regrowing them for more than a month. 

These very flavorful parts of the green onion plant (like other allium plants) is where the flower stems eventually appear for seeding. You can identify the onion scapes by a green bulb at the TOP of the stem. You can cut the entire stem and saute them to eat them. 

Step 1: Rinse the onions

Remove your green onions from the glass or cup the

Remove your green onions from the glass or cup they’ve been sitting in. I like to rinse them off so they’re clean. 

Step 2: Add soil to container and water

Add soil to your pot (you can use premade potting

Add soil to your pot (you can use premade potting soil or your own mix). I like to water the soil before adding it into the planter so it’s already moist. This prevents the soil from moving too much when you water it later. 

Step 3: Poke holes in the soil

Poke holes in the soil big enough for the green on

Poke holes in the soil big enough for the green onions and leave roughly 1 1/2 inches between each hole.

Step 4: Plant the onions

Gently stick the root of the green onion down into

Gently stick the root of the green onion down into the soil and cover about 2 inches of the white bulbs with the soil and lightly compact it so the onions won’t fall over. Depending on the size of your pot you can fit multiple green onions. For a standard 2 quart pot, I fit about 5-7 green onions.

Step 5: Water the pot and wait!

Step 5: Water the pot and wait!

Water the container and wait for your green onions

Water the container and wait for your green onions to grow. I check the soil every other day to make sure it stays moist. I like to add a bit of liquid fertilizer high in nitrogen on top to give it more nutrients. (Follow the instructions on your fertilizer if you would like to continue to give your plants more nutrients. I typically do this every 2-3 weeks). 

Common onion pests

Green onion has very few pests because it’s onion after all.

You may encounter thrips and maggots, but these are easily removed by manual removal, dish soap, or insecticidal soap.

Avoid using any synthetics if possible since this is an edible vegetable crop.

Plus, if you’re growing organic, you need to keep it organic. If pests are really a problem, you can consider greenhouse planting or moving your green onions indoors and grow in water.

All About Scallions

A cross-section cut of this onion reveals it&#8217
A cross-section cut of this onion reveals it’s A. cepa. Source: quinn.anya

Allium fistulosum, or green onions, are also commonly called bunching onions, scallions, Welsh onions, or Japanese bunching onions. It is likely that they were foraged in the wild before becoming popular in China and Egypt. Tokyo Long White, Evergreen, and Heshiko are some of the most popular varieties. 

Green onions look similar to the traditional onion, Allium cepa. They have tall, green stalks, and are usually 1-2 feet tall. They have slender white bulbs at their base that do not get large enough to form an onion. In hot temperatures, scallions will bolt to seed, forming a globe shape of tiny white flowers. 

Green onions are perennial and the scallion leaves can be harvested for several years in mild climates. All parts of scallions are edible, including the flowers. Thinner scallions will have a milder taste, while thicker onions will have a stronger flavor and hold up to cooking better. 

One interesting fact about scallions is that you can tell the variety by looking at a cross-section of the leaves where they turn white: if it is D shaped or flat, it is A. cepa, but if it is O shaped, it is A. fistulousum


When cut, green onions will readily regrow from th
When cut, green onions will readily regrow from the bulb. Source: jimmiehomeschoolmom

Now that you know more about the types of green onions, let’s learn how to take care of them so they can mature! Let’s go over more of the specifics on how to care for scallions. 

Sun and Temperature

Plant in a sunny location that gets at least 6 hours of full sun. Scallions form best in zones 6-9 and thrive in temperatures between 60-75 degrees Fahrenheit. If you plan to grow scallions through the winter, mulch around your planted bulbs in the fall with straw or other organic matter to protect them from cold temperatures and prevent weeds. 

In zones warmer than 9, you might want to plant your green onions somewhere in the garden where they will receive afternoon shade. Since onions like full sun, it is definitely possible to raise scallions in hot climates!

Growing green onions indoors is also an option, particularly for those who have cold winters. Make sure they have plenty of light and warmth during the cold season and you’ll have scallion harvests through the winter and well into the spring.

Water and Humidity

Morning is the best time to water to reduce soil moisture evaporation. This also allows foliage to dry out during the day so they’re less prone to disease.

Scallions are sensitive to drought. Aim for 1 inch of water per week. Use soaker hoses or drip irrigation. Ditch or “furrow” irrigation is another viable method. Dig a long trench in the soil an inch or two from your plants and flood the furrow, allowing the bulbs to absorb moisture. 

If you have sandy soil, you will need to irrigate more frequently. In a cooler season or mild climate conditions plants develop more slowly, so less watering is required.


Scallions prefer fluffy, well-balanced, and loamy soil. If you have poor soil, amend it with organic matter like compost at least six inches deep. While onion bulbs are able to develop in clay soil, they have a hard time if it dries out, and the soil may hold a little too much moisture for their liking. It’s best to amend to allow for good drainage while still keeping the soil moist.

To grow scallions, the optimal soil pH range is between 6.0 and 7.0. These bulbs can tolerate soil pH a little lower than 6.0, so if you’re planting them near tomatoes or other solanaceous plants, they’ll manage. If soil is too alkaline, these may struggle to get off to a good start.


Since scallion plants are leafy greens, you’ll want to fertilize them every regularly with a nitrogen-rich amendment. Liquid fertilizers such as fish fertilizer or comfrey tea have nutrients immediately available to your plants, so consider watering with a liquid fertilizer during the growing season to provide nutrients when your plants need them most. For a longer-term solution, use granular fertilizers that will be released slowly into the soil. Look for one that is high in nitrogen (the “N” in N-P-K). If desired, top-dress with rich compost. 


Most of the time, pruning is only done for harvesting purposes. Plants can be trimmed for cosmetic purposes, such as removal of wilted leaves, but otherwise should be left until it’s time to pick them.

If your green onions bolt to seed and you want to prevent seed drop, trim off the flower stalk. Often, you may experience leaf wilt during flowering as well. Early trimming of the bud and stalk (referred to as an onion scape) will redirect your plant’s energy towards leaf development. 

If you’d like to collect seed, let the flowers fully open. Onion flowers are pretty impressive. They create a large, almost ball-shaped umbel. As the flowers start to fade, tie a paper bag over the top and tightly secure it to the stalk. The seeds are very tiny. Cut the stalk once it begins to droop, and set it somewhere so that the head can dry out and the seeds can drop out of the flower.


One method of propagation is bulbs or “sets”. The best way to use sets is by planting them in late fall and overwintering them in the garden. In the spring they’ll start pushing up new growth.

You can also use nursery starts of Allium cepa, and plant them to achieve the green onion stalks. Keep in mind that only Allium fistulosum will produce tree green onions with no onion bulb. True scallions have a milder flavor than A. cepa, which has a stronger onion flavor. 

If you save rooted bulbs from store-bought green onion plants, you can easily regrow green onions. They’ll happily produce tall, green leaves every couple of weeks and give you a bonus crop. This works both indoors and outdoors, so if you’d like to save your young green onion bases from the supermarket and pop them into moist soil under a T5 light, you’ll see new growth rapidly emerge!

And, of course, starting from seeds is definitely an option. There’s a wide variety of seeds available for many different species of scallion or bunching onion types. Follow the directions in the “planting” section above for how to sow seed.

Reader Success Stories

  • Jay Tyler

May 2, 2019

    Jay Tyler May 2, 2019

    “I’m always putting onions in water, but they rot. Now I know how to save them and get more, thanks so much!”

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