Wait! Those green onion scraps. Why are you throwing them out!?!?!
Did you know that you can plant them in soil and regrow them for a virtually endless supply?
Or how about even just putting them in a vase (from the dollar store) in a pool of water?
Never buy green onions from the store again. Save yourself a few bucks on your next haul.
The best part? You can even grow them organically!
So let’s dive in and learn how to regrow green onion scraps- the DIY way.
Last updated: 8/5/21.
Quick care guide: Green onion
|Scientific name||Allium cepa|
|Other names||Scallions, spring onion, sibies|
|Soil type||Loamy, fertile, well-draining|
|Soil pH||6.0-7.0 (slightly acidic to neutral)|
|Sunlight requirement||Full sun|
|Bloom season||Spring, summer|
|Colors||White, green, yellow|
|Max height||1-3 feet|
|Max width||2 feet|
|Ideal temperature range||68-75F|
|Watering requirements||Often during first year of growth, spring, and summer|
|Days until germination||1-2 weeks|
|Days until bloom||60-90 days|
|Speed of growth||Moderate|
|Hardiness zones||6, 7, 8, 9|
|Plant depth||2-3 inches|
|Plant spacing||1-2 feet|
|Common diseases||Downy mildew, purple cloth, onion smut, leaf rot|
|Grown in container||Yes|
|Care level||Low (very easy)|
|Uses||Decoration, edible, indoor plant, recipes, seasoning, soups, salads|
Are green onions the same as scallions?
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.
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.
How many times can you regrow them?
You can regrow them as many times as you wish. When you replant them for the first time (using store-bought), you’ll end up with the same amount that you started with. Each plant gives rise to one plant.
But in my experience, people get addicted. They plant more and more so that their onion garden grows exponentially.
Then you can decide if you want to replant your harvest again to exponentially increase your yield. Or eat them all. The choice is yours.
Note that each individual plant will need to be replanted eventually. They lose flavor and will become thin and bland over time. This happens quickly in water compared to soil planting.
Once you get a little plot of them going, you can constantly harvest and then replant them over and over again so you get a bountiful yield each growing season.
Can you regrow green onions in soil?
Green onions can be planted in soil and while this method isn’t as cool as planting in water, it seems to have a higher yield.
Soil panting is boring, traditional, and old school, but it works. If you just want to get a guaranteed harvest, then soil propagation is the best choice. It also requires minimal care and leaves more room for mistakes.
When you have grown them in a contained environment, like a container of water, it makes it easy for nutrient buildup, hard water buildup, or other things that can negatively impact your onion production.
How about water?
Yes, you can grow it in water. You literally just need any old container filled with water and then show the onions in there.
They’ll drink up the water and then produce it for you. It’s way cooler to do it this way. When people visit your home, they’ll think you’ve got some crazy micro green experiments going on.
While it’s easier to screw up growing in water vs. soil, it’s also much more fun. You can do both if you want.
We’ll cover both techniques in this guide.
Should you regrow in soil or water?
Water planting leads to thinner shoots with fewer layers.
Over time, your plant will produce thinner and thinner shoots that’ll require you to replant it and start over.
Soil planting gives your scallions more nutrients so that it produces thicker shoots. Lots of people start with indoor water growing, but then move to soil planting after the novelty is gone.
You can do the same so you get the best of both worlds?
Growing in water will cause them to turn bland and lose flavor over time.
You can only repeat this 2-5 times before you need to start over. If you want to minimize your work and get more flavorful onions, grow them in the soil for best results.
How to grow green onions from scraps
So here’s the meat of the guide. We’ll cover both ways and you can pick whichever you prefer. But first, you’ll need to get the actual green onion scraps.
Choosing green onions for regrowing
It’s not hard picking out the best green onions to regrow.
All you need to do is use your eyes! Just like picking out the best of the bunch of any other veggie or fruit, look for signs of a virulent plant.
- Lime green appearance with minimal yellowing
- Firm, but not over rigid
- No soft spots
- Dark green foliage
- No signs of fungus, dark spots, or rot
- Visible roots coming out of the bulb (the white part)
- Organic if possible
This should get you off to a good start. Even if you find any random onion from the store, it should be good enough to regrow your first batch.
Prepping your spring onions
First, we need to prep the greens before we can replant them. Prepping is simple and it’s basically what you’ve already been doing every time you cooked them in meals.
- Wash the green onions thoroughly. If you do vinegar soak or use special cleaners to remove pesticides, do it now.
- Get your favorite paring knife and cutting board.
- Cut the white part of the onion from the green part. This is usually the bottom 2-3 inches of the vegetable. Do NOT cut off the roots that stick out from the bulbs. You need them to successfully root it.
- Give your bulbs a good rinse to remove any dirt or debris. This will help prevent fungus or rot.
- Inspect the bulbs for any signs of infection. When in doubt, throw it out!
- Repeat as needed.
How to propagate green onions in water
Next, let’s cover the process of regrowing it.
Here’s what you’ll need:
- A container to grow the onions in (mason jar, vase, can, pot, cup, bottle, etc.)
- Water (purified if you have hard water or municipal water), you can also use bottled water or filtered water
- Toothpicks (optional- only needed if the container you’re using is deeper than 2-3 inches)
As you can see, you don’t need much to get started. That’s the beauty of it. Keep it simple, right?
Take your container and then fill it up with water. Only fill it to the point where the water level barely reaches the top of the green onion (the cut end that you made). It should NOT be fully submersed.
Take your cut scallions and then place them into the container. They should stand upright with the root end sinking to the bottom. They shouldn’t float. If they do, soak them for a bit to get the air out or swish them around.
If your spring onion doesn’t stand up because the container is too wide, use the toothpicks and stab through each onion like a skewer.
The toothpicks should be aligned over the top of the mouth on the container and hold the green onion in place. If it still doesn’t work, use something else or a container with a narrow lid.
Party cups work well because you stab through the cup edge with the toothpicks.
That’s it. Your onions are good to go! Wasn’t that easy?
Take the container and put it next to a bright window with indirect or filtered sunlight. Do not put in direct sunlight because it’ll scorch the plant or lead to algae growth. However, the room should be bright and room temperature.
Leave it there and let it sit. Over the course of a few days, you should see that the roots grow out and the bulb slightly changes tone. You don’t need to do anything at this point other than sit and watch. Be in awe.
Now comes the work. You need to swap out the water every 3 days with clean water.
Do a full water change by dumping out the dirty water and then replacing it with clean water. Remember to use soft water or purify it if needed. If you see that the water quickly gets dirty, it may call for a water change before the 3-day mark. Do it when it makes sense. It’s not rocket science!
Watch for any signs of root rot or fungus. If you see the roots looking dirty or the plant starts to get some nasty fungus growing on it, you need to start over. There’s no point in trying to save the other bunches you have growing in the same container because they’re likely infected with the same virus.
Next time, wash the onions with a cleaner or more thoroughly. It’s possible that it may have been infested from the supermarket also. Try organic spring onions because I think they’re easier to work with.
The shoots will continue to grow. You can harvest as soon as the green color is solid. There’s a transition from the white bulb with the roots to the dark green shoots.
When the shoots are solid green, you can cut them off with a pair of clean pruners. This is usually about the 4-5 inch mark from the bulb.
How to regrow green onion in soil
Planting in the soil is the original, traditional way. I find that while growing them in the soil produces thicker scallions compared to water growing. It also leaves more room if you mess up.
You can do this if you already starting growing them in water. If you’re starting with fresh onions, that works best since it avoids the plant shock of moving them later on.
First, prepare the green onions for regrowing as outlined earlier on this page.
Next, find a suitable location in your garden. It should be sunny, but not too hot. Partial shade works fine to prevent scorching. The soil should be rich, fertile, and well-draining. You can use a premed potting mix or build your own.
No need for any fancy amendments as long as it meets the basic parameters outlined below in this guide.
Dig up holes about 1 inch deep and 2 inches apart. To maximize space, dig in rows as wide as your plot can support.
Place each green onion bulb into its hole. Then gently cover with the backfill soil.
Water generously the first time around to establish water pathways. The soil may take a few minutes to drain but should drain quickly the next time you water it. If not, you need to switch soils or use a raised planter.
Continue watering and watching the shoots grow. Look for any signs of pests or plant disease. Green onion is generally resilient so there’s little to worry about.
Over time, your bulbs will establish roots. You can test it by gently tugging on the shoots. If it’s firm and stays in place, you know that the rooting is successful.
Your plant is ready for harvest when the shoot turns dark green and doesn’t get any greener.
Can you regrow green onion in container or pots?
You can do the same process in a pot or container if you wish.
This gives you the opportunity to move it around and test different environments in your garden. More sun. Less sun. Etc. Just don’t overcrowd it. You can fit 7 green onion stalks in a basic half-gallon container. Space them out and use the soil to hold them in their own little homes.
When you plant in soil, the white bulb should be covered. Check the water levels daily. It should always be moist, but not wet. You can supplement with some liquid fertilizer as directed, but this isn’t necessary if it’s growing fine.
Transplanting from water to soil
If you started off by growing them in the water, you can transplant them to the garden after a week.
This will give them plenty of nutrients which produces thicker shoots. If you want the absolute best tasting green onion, planting them in your yard is the way to go!
Transplanting them is easy since there’s no soil to dig them out of. Take the bunch and find a good spot in your garden to relocate them to. The soil should be fertile, rich, and suitable for vegetable growing. See the later section for more details on proper care.
When you remove each onion shoot, dig a hole that’s as deep as the water that you originally had them in. This should be around 2-3 inches per grown shoot.
Put the shoot in the dirt and then cover it gently with soil. Water generously the first time around, then switch to reduced watering.
Your plant will likely turn yellow and wilt for the first few weeks as it adjusts to the new environment. This is very stressful on your onion because it’s basically moving to a new home. AKA plant shock.
After it acclimates, you can continue harvesting them by cutting off the shoots as needed. You can get 5 or so harvests from a single green onion stalk before you need to replant it. It grows thinner over time and will need to “reset” itself so it can continue to produce for you.
Green onion care
Here are some quick guidelines for proper care of your green onion.
Green onion grows best in USDA hardiness zones 6-9. You can grow it outside of this range by growing it indoors over water. It’s not picky.
Green onion does well in rich, fertile, well-draining soil. You can use a premed mix made for allium plants or even a generic vegetable mix. Water retaining is a plus. Add some rocks at the bottom to help encourage draining.
Plant each bulb about 2-3 inches deep. The white bulb should be nearly covered, but the light green part should be above the soil line.
Space each green plant onion 1-2 feet apart. They don’t need a lot of space to thrive and do well in large groups contained into one small area. You can get a lot of harvest from them even in the tiniest gardens.
Green onion prefers a slightly acidic soil with pH values between 6.0-6.8. While it’s not going to make or break your harvest, it can help produce a zestier flavor and more yield.
Water regularly. It should never be wet, but always moist. Don’t let it dry out between watering sessions. Green onion loves water and you need to supply it. Don’t forget to account for rainy days or periods of hot sun/drought.
Plant in direct sunlight if you’re within the right hardiness zone.
If not, plant accordingly. Hotter zone? Plant in partial sunlight.
Colder zone? Plant in direct sunlight or indoors. If you’re regrowing in water exclusively inside your home, plant in a south-facing window.
Green onions like moderate to high humidity.
Think about it: Growing them in water is basically 100% humidity.
If you’re going outdoors, the natural evaporation and soil saturation of water will do fine. If you see that your soil is constantly drying out, increase watering frequency. You can also use mulch or switch to moisture-retaining soil.
Green onion grows best in temperatures between 60-86F. It’s prone to scorching under the hot sun and also doesn’t grow well in cold water. Moderate temperatures are best.
If you’re growing in zones 6-9, you should be fine. If not, grow it indoors if it’s too cold. Greenhouses also work.
A liquid-based fertilizer can help increase plant growth and thus produce more yield.
Onions grow shallow roots, so the fertilizer should be applied within the top few inches of soil (3-5 inches). Use any fertilizer that’s suitable with an NPK of 5-10-10.
They like plenty of nitrogen for growth but will need double the phosphorus and potassium. Use as directed. Note that fertilizer isn’t required, but will help your onion produce more often.
Scallions can be harvested quickly during the growing season. They’re usually ready every 2-3 weeks. You can cut as needed.
Each shoot can be harvested up to 5 times before it needs to be replanted. You’ll notice this as the plant starts to get very thin when you harvest it.
It topples over and flops as soon as you harvest it, rather than having that sturdy, firm feel to it. It doesn’t affect the flavor much but may result in a duller taste that’s blunt.
After harvesting, the green onion should be consumed immediately. They’re perishable and will go bad quickly. If you need to store them, put them in the humidity drawer in your fridge. They need 90% or higher humidity to stay fresh. They can stay fresh for up to a week at 36F.
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.
Green onion disease
There is some green onion disease that you should be on the lookout for.
Some of these are downy mildew, purple cloth, onion smut, leaf blight, or neck rot. All of these are likely caused by overwatering and poor air circulation.
Consider reducing water, harvesting more often, or using fans to help evaporate the water. If you notice any weird colors, spots, or wilting of your green onion, it should be pruned.
Then you should start with a natural fungicide to get rid of the issue. Avoid watering the leaves and make sure the mulch around the base doesn’t touch the foliage. Water at the base.
Propagating green onion
Propagating is as simple as repeating the process you did when you prepped them for regrowing.
You just uproot the entire onion shoot, snip off the edible portion, then replant the bulbs.
That’s all there is to it. Replanting green onions is so easy. It’s the same process every time.
Obviously, the best use for green onions is to eat them! Use them in your current culinary recipes that you already cook.
Except now you have one less thing to cross off on your shopping list. Additionally, if you’ve never tried organic green onions before, now’s a good time to do it.
Some of my favorite recipes that you should deifnitely check out:
- Green onion scallion soup
- Scallion pancakes
- Green onion rolls
- Green onion potatoes
- Onion rice
You may find these references useful on your journey to grow the best darn spring onions possible:
- Regrowing Green Onions in Water … – Reddit
- Green onion | plant | Britannica
- Get more $$$ out of your green onions … – Reddit
Are you regrowing your spring onions?
Growing them from scratch is easy, rewarding, and provides you with a bountiful harvest each season.
Anyone can grow them because they require little to no maintenance. It’s just harvest upon harvest!
Do you have any questions? Post a comment and let me know. If you already grow these, post your tips/tricks for other readers!
I took interest into microflora and microgreens before it became mainstream. The idea of growing an entire ecosystem on a tiny scale simply was astounding. That’s where I discovered that I actually like raising plants and wasn’t as much of a black thumb as I thought. Now, I’m relaying what I’ve learned to others who are getting into the hobby in a way that anyone can understand.