★ How to Plant a Sprouted Onion ★
Quick Answer: Yes, you can plant a sprouted onion and grow new onions from it. Gently peel away the outer layers, separate the individual onion sprouts, making sure each has some roots attached, then plant them about 1 inch deep and 4 inches apart in a sunny spot. Keep the soil moist but not soggy. In about 3 months, each sprout can grow into a new onion!
If you have an onion sprouting in your pantry, don't throw it away! One sprouted onion can often be separated into multiple plants, giving you two, three, or sometimes even more new onions.
I've used this method to regrow grocery-store onions in my own garden, and readers have been successfully following these steps since I first published this tutorial in 2020.
Check out the step-by-step tutorial, below.
Step 1: Peel the sprouted onion.
To get to the part of the onion you can plant, you need to peel away the layers of the onion bulb, all the way down until you get to just the clump of green sprouts.
Tips:
- If your onion has sprouted, chances are some of the outer layers will be soft and may be starting to rot. If not, you can still eat the outer layers of onion that are not rotten.
- I don't use a special tool for this step. I just peel the layers off with clean hands. Using a knife may cut into the sprouts.
Step 2: Separate each onion sprout.
Carefully separate each sprouted section, making sure each one has roots attached.
Tips:
- I use a serrated kitchen knife but any knife will work.
- Ensure that each sprout has some roots attached.
Step 3: Plant your onion sprouts.
Your onion sprouts will survive for up to 3 weeks before you need to plant them. Store them in a cool, dry place. Letting them dry a little before planting is ideal to prevent rotting.
Tips:
- Do not soak or store onion sprouts in water before planting. This can cause rot.
- Plant onion sprouts in full sun. Onion plants require 12+ hours of direct sunlight a day.
- Loose soil allows the onion bulb to grow.
- Onion plants don't need to be buried very deep. Plant each sprout just 1" into the ground and space them at least 4" apart so the bulbs have room to grow.
- Planted onion sprouts will take about 3 weeks to look perky.
Step 4: Care for your onion plants.
Water and weed around your onion plants as they grow. Fertilize as needed.
Tips:
- Onion plants prefer to be watered in cycles rather than every day. Water onions about once a week unless the soil and plants start to visibly look too dry. Over-watering can cause rot.
- Fertilize your soil. Onions need nutrients to grow so make sure to offer them rich soil. You can use organic (manure, compost, etc.) or store-bought fertilizer to ensure your soil has the nutrients it needs to grow to its full size. Read more about how to test your soil for acidity.
- Onions need well-drained soil. Standing water can cause rot.
Step 5: Harvest your onions.
Onion plants should grow for about 3 months to reach optimum size which is when the bulb reaches the size of a baseball. You will be able to see the top of the onion as it grows and can get a good idea of its size without digging it up. Harvest by pulling the onion out of the ground and then brushing them to remove dirt.
Tips:
- You do not want your onion plant to flower. If it does, the bolting process has started and the bulb will not continue to grow. You can still harvest the onion bulb, it may just be small. Sometimes due to changes in temperature, an onion plant will flower prematurely. This can happen just as a fluke too so it's best to plant multiple onion sprouts for better odds of scoring a full-grown onion!
- Frost may cause the green top of your onion plant to die off, so your bulb will need to be harvested shortly after that
How to Store Harvested Onions
Onions are ready to eat as soon as you pull them out of the ground. If you want to store them for later, you'll want to cure them first.
- Curing is easy. After harvesting, let onions dry in a warm, dry place with good airflow until the outer skin and stems are completely dry. You can lay them on dry soil, hang them, or place them in a wire basket or mesh bag. Rotate them as needed so all sides dry evenly. Curing typically takes 2–6 weeks and helps prevent rot during storage.
- Do not rinse onions to clean them off. You want to keep the onions dry to avoid rot. Allow them to dry then you can brush away any dirt.
- Once cured store your onions in a cool, dry place. Cured onions, depending on the type and size, can be stored for as long as 10 months!
And if your onion begins to sprout before you get to use it... well, you now know what to do! Use that sprouted onion to grow more onions!
★ FAQs ★
Onion plants rely on insects to be pollinated. However, when you're re-growing an onion from another onion that has sprouted, that plant has already been pollinated. So you can regrow it indoors.
Onions require a substantial amount of sunlight to thrive. They need 12+ hours of direct sunlight. Onions to not grow well in shade or even in indirect light. So if growing onions indoors, you will most likely need to use a grow light to provide enough quality light to meet their needs.
This depends where you live. Generally, spring is when you will want to plant. You will want to make sure that the temperature does not drop below 28°F (-2°C). You can keep your onion sprouts indoors for up to 6 weeks before transplanting to the ground if needed.
Note: The ideal soil temperature for onions is 50°F (10˚C) and above.
Yes, you can regrow any color onion that has sprouted! White, yellow, or red.
★ Recipes You'll Love ★
Once you've grown new onions, try making some yummy food with them!
I have a ton of easy recipes to give you ideas for what to make with your garden-fresh onions.
Browse all my super easy recipes and Pin your favorites for later.
★ More to Grow ★
Did you know you can also regrow a sprouted potato?
Esther Colleen Weaver says
This isn't no comment but I want to tell thanks for the tip how to grow potatoes and onions..
Payton says
Hi! Thanks for all the info!! When you said, 'Your onion sprouts will hang around for up to 3 weeks' does that mean I can't plant them for three weeks?
Angela G. says
Hi Payton, you do not need to wait to plant. Three weeks is about how long they will stay plantable before they can start to dry up.
ID Spud says
I knew you could use the bottoms of little green onions. Good info about peeling down to the green onion part. I was going to just put the whole thing in the ground!
Angela G. says
Yes, it's one of those things you don't know that you don't know! Best of luck planting and gardening.
Becky says
Thank you for the info!!! I just started 7 starts in my house. Waiting for summer to plant in the green house. (Alaska). With food going up in price. We think before we toss away
Angela G. says
Good luck with planting in the green house! I agree, we have to save where we can.
Tish Webster says
@Becky, I’m doing the same thing..I’m actually trying to grow my own garden
Biga says
Very useful information especially the removing the skin
Dominique byrd says
I broke my sprout by trying to peel too much. 🤦🏾♀️ Going to try again next time
Angela G. says
Oh darn! You could still try to plant it if you want as long as there are roots you can probably grow something. It might not be perfectly round. Onions are pretty hardy.
Sheri says
I planted 19 sprouts from store bought onions that did their thing before I could cook with them. They are out in the garden bed as of today. Thank you for your very helpful guidance.
Angela G. says
Sounds like you will have a nice harvest in a few months. Exciting! Glad I could help!
Teresa says
Thank you, Angela. I will let you know how this works for me....
Angela G. says
Great! I'd love to hear how this works for you, Teresa!
consuelo barra says
Thank you for your information.
Can they be planted in a pit indoor?
Angela G. says
Hi Consuelo, Since onion plants require pollination, I believe they would need to be planted outside where there are insects such as bees to pollinate the plants.
linda says
@Angela G., Onions are pollinated by insects like bees, but pollination is only necessary for producing seeds, not for growing the edible bulbs.
Gloria Russell says
These sprouts resemble green onions. Are they? Can you eat them as you would a green onion?
Angela G. says
Hi Gloria, they are not the same as green onions but are similar and are edible. The flavor is a bit more mild than a green onion.
tricia lewandowski says
It's February and we just got a huge snowstorm , so when do I plant My green Sprouts
Angela G. says
You can try planting indoors in a very sunny spot in a large, well drained pot.
paula says
First onion experiment planted today
:-))
Angela G. says
Exciting! Good luck. 🙂
Stephanie says
@paula, how are yours doing? I just planted for the first time today. I’m so excited!
I just planted my first onion along with a sprouted garlic clove and 12 jalapeno seeds (egg carton starter) today! I also started composting! I'm excited 😁 says
@paula,
Jenna says
Thank you for this info! I just planted my sprouted onion. When I peeled mine, there was nothing to separate. There was only 1. So I guess it was just a single one maybe. We’ll see!
Angela G. says
Could be that it’s just one! Sometimes it looks like there is just one but there are actually two and you need to remove one more layer. You can usually tell if there are two though by looking at the top. You’ll still be able to plant it and if it’s two you’ll get two onions shaped like half circles. Good luck! Thanks for the feedback.
William says
Thanks for the help! My partner and I just *planted* the sprouting onions without peeling and splitting them!
Now, instead, we've got 4 onions growing!
Angela G. says
I did the same thing at first. Now you know! 🙂 Good luck. Enjoy your 4 new onions!
Antoinette says
Thanks for the great info. I have 2 huge red (spanish) onions that I had forgot in the garage. They had grown in the dark and cold with long green leaves (?), So I decided to look up how to save them. Thanks for bunches of great photos and information.
Angela G. says
Hi Antoinette, You're welcome! Good luck growing your red onion sprouts!