Growing Onions indoors – 6 Ways to Grow Onions in Containers

This article shows you how to use onions as indoor plants. Growing onions indoors is a fun project and one that the kids will love to help with.growing onions indoors in containers Onions are easy to grow both outdoors and inside.  They are one of those vegetables that we use often and the demand for this means that they are a great vegetable to grow.Growing onions indoors

Many gardeners think that they would love to grow onions, but they also assume that one needs a large amount of space to grow them. This is not necessarily the case and there is an easy answer to this problem. 

Just try your hand at growing onions in containers. Doing this will allow you to have onions growing on a small patio or deck garden, or even have them growing inside your home.

There are many types of this versatile vegetable. Find out about the onion varieties here.

If you don’t have the space for a  full scale vegetable garden outside, you can still grow onions indoors.

You can even have an endless supply of them if you do it just right since onions are a cut and come again vegetable.  (they will regrow from the original stock with roots.)

Onions are a very persistent vegetable. They will sprout, regrow, and sprout again. Just look at this basket of them. Many have already sprouted and could be used to make new plants.basket of sprouted onions

Growing onions indoors gives you an endless supply when you need them.

There are lots of ways to grow onions outdoors, but they usually require a big garden space. Outside, onion sets are often used,(basically small undeveloped onions) but when we are thinking about the task of growing this useful vegetable inside, we have to think outside the box.

Most of these ideas will end up giving you onion tops, rather than onion bottoms, since those require quite a bit of space to grow.

But the sprouts of onion have a lovely taste, too, and can be used in all sorts of recipes, in addition to using them as garnishes.Growing Onions Indoors is easy

For today’s project we will focus on the ways to grow them in a more confined area. Here are a few of the ways to grow onions indoors.  Kids will love these projects too!Spring onions will re-grow from roots

Growing onions in containers

Growing onions in pots is easy.  You won’t get a large crop like you do outside, but the top will give you a part of the plant that you can use in recipes. Place a small whole onion in potting soil in a pot and it will spout new growth.  

You can either slice off the onion where the roots are, or place a small whole onion on soil and it will grow, in time. When it has developed repeat the process as often as you like. 

Growing onions in water

Onions don’t even need soil to grow. Growing onions in water is a project the kids will love because they can see the roots growing through the sides of the glass.

If you place a sprouted onion with the roots down in a glass of water, it will continue to grow on the top with new shoots. 

You can either cut off the top part and use it in recipes, or plant the whole onion, roots and all, in soil and watch it grow.

Onions growing in water.

Onions can be a decorative plant too, as this photo shows. The onions are sitting in a bowl of water lined with pebbles. I also force paperwhites using the same technique with great success.

Onions in water with rocks

All types of onions will regrow.  One of my latest experiments was to try to grow vidalia onions from bottoms that would normally end up in the trash or compost pile. My onion sprouted quickly and gave off new growth in just a few days.

Feeling cooped up and need a project to keep you busy? Try growing onions indoors. Check out the tips on The Gardening Cook. 🧅🧅🧅 Click To Tweet

Growing onions from onions

Don’t discard those old onion bottoms in the trash.  You can create an endless supply of green onion tops without ever having to buy more. This can be done with all types of onions.

The roots of onions are very persistent.  In this photo whole onion bottoms are planted in soil and the green sprouts are growing.  If you cut off the green parts to use in salads, more will grow.Growing onions bottoms

Cut and come again onions

Growing green onions indoors is a cinch! This is one of my favorite ways to grow onions.  I buy one clump of spring onions at the store. Then I place them in a jar of water and cut just the green tops for recipes. 

You will have new growth before you know it and never have to buy spring onions again.  See my tips to re-grow spring onions in water here.

Growing green onions in water can be done in just one week.

Growing Onions Vertically in Soda Bottles

This idea is such a fun one for kids to do.  Grow onions vertically on a window sill.  You will need a 5 liter bottle that you have made holes in.

Fill the bottle with potting soil and onion sprouts and watch your harvest grow indoors! The kids will be fascinated growing onions when they see the soda bottle covered with onion tips that have grown out of the holes in the bottle.Growing onions vertically

Growing Onions from Seed

Spring onions don’t take up much room outside and will send up flowers quite easily. I had one batch that took up just a square foot of space and it lasted about 4 years before it finally gave up the ghost.

Onions are biennials and will produce seed in their second year.

The plant sends up stalks with flower heads on them. These are called umbrels. When they go brown, cut them off the plant and place them in a paper bag and allow them to dry completely for a few weeks.

Once dry, give the bag a shake to separate the seeds from the other matter in the flower head and store them in a cool, dry place.

The seeds can be used to plant in soil both indoor and out and spring onions grow very easily indoors from these seeds. (Store bought seeds work too.) 

Grow lights are a big help for starting seeds indoors.

Flower umbrels on on spring onions produce seeds.

Planting sprouted onions

Onions sprout easily and that is good for getting more plants for free.  This project can be done on a deck. 

Get a 4 gallon container and add some wood chips about half way up.  Fill the rest of the pot with potting soil. (the wood chips will act as drainage.)  

Keep the soil evenly moist and the sprouted onions will grow for you.  The roots on the bottom will love the new, rich soil!

Sprouted onions will grow

Do you ever reach into the onion bin and find an onion that has sprouted where the sprout actually splits the onion?  Don’t just use part of it and discard.  Put that sprouted part to work. 

Slice into the onion to expose the sprout and carefully cut the onion in two (take care not to disturb the sprout).  

Carefully cut around the sprout and plant.  You can use the part not planted but will end up with another onion too! 

This onion has sprouted and split the skin

Growing onions from sets

If you are interested in growing real onions and not just their tops, buy onion sets.  These are small, dry onion bulbs that have been grown the previous year. They are very easy gardeners to grow. Growing onion sets in soil.

Just press the small onions into the soil up to their tops, barely covered with soil 3-4 inches apart in rows. Since whole onions require room to grow, you won’t be able to grow many unless you have a really large pot.

Sunlight is also an issue.  Onions need a LOT of sunlight, so a south facing window is best. Normally, whole onions are grown outdoors or in pots on a patio.

The tops will be ready in 20- 30 days.  Whole onions take 100 to 175 days to reach maturity.  

Admin note: This post first appeared on my blog in January of 2017. I have updated the post to add more information and photos and also added a few new ways to grow onions indoors. I’ have also included a printable project card and a video for you to enjoy.

Would you like a reminder of this post for ways to grow onions indoors? Just pin this image to one of your gardening boards on Pinterest.How to grow onions indoors collage

Have you discovered other ways for growing onions indoors?  Please share your tips in the comment section below.

Yield: Regrow onions from parts of whole onions, from their roots or from pieces.

Growing Onions indoors - 6 Ways to Grow Onions in Containers

Grow onions indoors

Growing onions indoors is a fun project to get the kids involved in gardening

Active Time 30 minutes
Total Time 30 minutes
Difficulty easy
Estimated Cost less than $1


  • Sprouted whole onions
  • Onion bottoms
  • Seeds from onions that have flowered
  • Spring onions
  • Shallots]
  • onion sets


  • Water
  • Soil
  • Rocks
  • Plastic bottle and sharp knife


  1. Place whole spring onions in a glass of water. They will sprout. Cut off the green tops and more will grow.
  2. Place a whole sprouted onion in a soil. You'll get sprouted tops for salads that will regrow.
  3. Cut wholes in a soda bottle. Add soil and place shallots in the whole area. They will sprout green tips.
  4. Place a whole onion in a glass of water. It will sprout and grow leafy tops
  5. Place seed onions in large pots of soil, they will grow whole onions.
  6. Place large scallions in a bowl of water over pebbles. They will continue growing leafy tops.
  7. Plant onion sets in soil. You'll get tops in about 30 days and whole onions in 3-6 months.
  8. Collect onion seeds and use them to grow onions. (spring onions are best for doing this indoors)

Disclosure of Material Connection: Some of the links in the post above are "affiliate links." This means if you click on the link and purchase the item, I will receive a small commission from the sale, but the price is the same for you. I am disclosing this in accordance with the Federal Trade Commission's 16 CFR, Part 255: "Guides Concerning the Use of Endorsements and Testimonials in Advertising."

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  40 comments for “Growing Onions indoors – 6 Ways to Grow Onions in Containers

  1. Joanne Castle
    09/05/2013 at 1:52 pm

    Looks like fun!

  2. Vicki Bruni
    09/10/2013 at 10:12 pm

    I think that the idea of growing onions indoors is great!!

    • Stella
      03/31/2018 at 10:53 am

      I tried growing an onion by starting it in a glass of water. I had great looking roots so I put the onion in soil. After a few days the onion was getting moldy. I kept it for a few days but am thinking about throwing it out. Can you help me

      • Carol
        04/03/2018 at 10:08 am

        Hi Stella. It sounds as though the onion rotted when you planted it. Once this happens, there is nothing you can do. Carol

  3. Josey
    11/28/2013 at 4:48 am

    Wonderful idea

  4. Kathy
    08/31/2014 at 1:02 pm

    This is great I am starting right away

    • admin
      08/31/2014 at 10:20 pm

      Hi Kathy. God luck with them! Carol

  5. Tammy
    07/31/2015 at 12:51 pm

    How can I get the hole big enough for the onion to be pulled through after it’s grown – and yet not so big that the soil falls out?

    • Bill Lenz
      05/02/2020 at 2:38 pm

      Use burlap or or cheese cloth.

  6. Edrece
    08/27/2016 at 3:13 am

    I’m Kind of confused here im only 16 and Ive just started my own vegetable garden Can Some one explain this in dummy terms

    • Carol
      08/27/2016 at 10:21 am

      Which part is confusing to you?

  7. Nadia
    04/30/2017 at 10:05 am

    If i planted a red or yellow onions​ in a pot, are they going to produce a real red and yellow onions again?! And when i should harvest them?
    Thank you.

    • Carol
      04/30/2017 at 12:54 pm

      Hi Nadia. Probably not if you keep them in a pot, unless it is large and kept outside. Onions need the coldness to develop a bulb. You could start them in a pot and then plant in the garden, but it does take months for onion bulbs to form.

      • Nadia
        05/02/2017 at 7:46 pm

        Thank you so much 🙂

        • Carol
          05/02/2017 at 9:44 pm

          My pleasure Nadia. Carol

  8. Jess
    09/09/2017 at 5:05 pm

    Do you only get one onion from the roots and sprouts.?

    • Carol
      09/09/2017 at 8:34 pm

      Yes but you can divide it again, with each part having roots and a growing tip. Carol

  9. Lena
    02/22/2018 at 2:13 am

    Thank you for sharing! My little tribe and I are planning on having an indoor garden this year full on and we all love onions 🙂

    • Carol
      02/22/2018 at 9:46 am

      Hi Lena. Hope you have fun with it with your tribe! Carol

  10. Toni
    03/02/2018 at 9:59 am

    I’m just interested to know if you can grow them in planters as houseplants not to harvest. I like the long green growth and would just like a house plant. Can that happen

    • Carol
      03/02/2018 at 10:58 am

      Hi Toni. Yes, you can grow them this way as long as you have them in a very sunny window. Vegetables need a lot of sun even when grown as houseplants or they will “reach” for the light and get spindly. Carol

  11. Jesse
    04/28/2018 at 9:46 am

    Planted mine less than a week ago.. I was going to add one more sprouted onion to the pot, but when I dug up the 2 onions that are growing (to repot with the 3rd onion) I realized just how much space the roots take up.. So I’ve decided to report one onion per 5 inch pot… Or, wouldn’t the roots choke each other out?

    • Carol
      04/28/2018 at 11:31 am

      :Hi Jesse. Great photo! If you are growing them for the tops, it won’t matter so much if they are crowded. Trying to grow whole onions is more tricky and is best done in larger pots or outside in the ground. Carol

  12. Jesse
    04/28/2018 at 9:53 am

    I’m also growing garlic inside that has sprouted .. Its just as easy as growing the onions.. All for the yummy greens from onions and garlic

    • Carol
      04/28/2018 at 11:30 am

      Thanks for the tips and photo!

  13. Des
    06/30/2018 at 7:17 pm

    Hi Carol! Someone gave me this as a gift. What should I do to keep it going??

    • Carol
      07/02/2018 at 10:46 am

      Hi Des. What you have is called a false sea onion. (Ornithogalum caudatum) It is not an onion. The bulb grows above ground and reach about 4 inches across. With a bit of luck you will get a flower stalk that has small, white fragrant flowers with green, central stripes. Most parts of the plant are considered toxic. People who handle the plant can get Dermatitis so wear gloves when handling it.

      The plant likes some direct sun but will scorch in hot, sunny, dry locations. Dry out slightly in-between watering but don’t let them dry too much or they will go dormant. The little bulbets will grow into new plants if you put them in soil.

      It is quite a rare plant and not commonly found for sale.

  14. Erin Davenport
    10/25/2018 at 9:34 pm

    How can I grow the onion inside to get a bug bulb? Or should i just want until the spring to plant?

    • Carol
      10/26/2018 at 1:17 pm

      Hi Erin. Onions grown indoors are unlikely to form a bulb. Onions like a long cold period that only happens when the ground gets cold outside. You could try planting it in the spring outdoors to see if it would develop that way. Carol

  15. Brooke
    11/15/2018 at 5:39 pm

    Will onions continue to grow with snow on the ground? If so, how do you dig them up once the ground freezes?

    I tried to dig some of them up yesterday. I don’t know if I planted them too closely and they crowded….or if I just didn’t give them a long enough grow season. I planted around late May/early June and I dug them up on November 14th. The ones I dug up are very small…the onions are about the size of cherry tomatoes. I left some dirt in the bag, and placed them in my fridge to keep them cool until I could figure out what to do with them. They otherwise look healthy, and the greens on top are mostly undisturbed.

    If I replant them in house containers, will they continue to grow?

    If not, I will just clean them up and eat them. Or recycle them into new plants. If you have any ideas or suggestions, I am certainly open to hearing more.

    • Carol
      11/15/2018 at 7:08 pm

      Onions can take quite a bit of cold. But if the temps will be below 28 degrees or so for a long time, it will damage them because ice crystals will form. Onions can take a few light frosts about 31 degrees or so with no problem but any longer than that they should be harvested.

      Onions will grow in doors but light is often a problem. You can supplement the light with fluorescent bulbs set close to the onions to give more sunlight if your pots can’t be placed right in the windows with direct sunlight.

  16. Brennen Olsson
    04/16/2019 at 4:49 pm

    hello i found this website because i was in my room and i had an onion seed just sitting there and it started sprouting and i dont have any soil so i was looking up if i can just put them in water but while i was looking i became very interested to plant onion because they are very cool and unique

  17. c
    07/24/2019 at 4:28 am

    i was googling for this as I had extra onions at home.
    lol thanks for sharing your knowledge with us Carol!

  18. Pat Mason
    07/24/2020 at 8:11 am

    I cut the bottoms off of Vidalia onions this time and got them rooted quickly in water. Then I put in dirt in inside pots. The round bulb developed and then the green shoot grew out of the top. A couple had multiple shoots so I carefully split them and repotted each in a separate pot. The bulb portion is totally above the dirt. Is that the part that will continue to grow and become the onion bulb? Do I leave above the dirt line or do I need to put the bulb slightly under the dirt?

    • Carol Speake
      07/24/2020 at 1:04 pm

      when growing onions from pieces, it is mainly the tops that will regrow. To get a whole onion bulb to grow is difficult unless you use small seed onions.

  19. 08/22/2020 at 5:53 am

    i tried to grow onions in my kitchen near my window but the results were not nice, i couldnt grow even a single onion lol

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