Growing Onions In Containers: How To Grow An Onion From An Onion Indoors

growing onions in containers

Onions are really easy to grow from another onion. If you have one that looks like it’s sprouting, or has a bit of green growing on it, it’s already starting to grow! Growing onions in containers is also a really simple way to keep onions available to you year round, and from your own home.

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*It can take a few weeks to see any growth. But if you’ve been waiting a while and still see no regrowth, it could be because the onion has been modified so it will not grow – they do this so you are forced to buy more. One way to initially combat this problem is to use an old onion, one that’s already sprouting in your pantry. The other is to use an organic onion, as they’ll be less likely to be modified.

What you’ll need

There are only a few things you’ll need initially for growing onions in containers. You’ll need an onion, a knife and cutting board, paper towel (optional), a small pot for the onion to start in, some dirt, a bit of water, sunlight, and patience!

Growing an onion from an onion

Prepare the onion

cut up onion next to pot of dirt

Start by cutting off about 1-2 inches of the bottom of the onion (where the little wisps of roots are). This is what you’ll be using. Cook the top of the onion in your favorite recipe!

Next, let the onion base dry out for a few days by leaving it out in a dry area. This helps to create a scale around the onion so it doesn’t rot in the dirt. You can wrap it in a paper towel during this stage to keep the smell from being quite as noticeable. (Letting it sit is not required, but suggested.)

Planting the onion

The next step of growing onions in containers is to actually plant! Fill a small container (ideally one with holes at the bottom so excess water can drain out) with dirt, and water lightly. Make a hole in the middle of the dirt, and place the onion (roots down) in the hole. Cover the onion with at least 1/2 inch of dirt. Water again over the spot where you just planted the onion.

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base of an onion in a container with dirt

Place the pot in a sunny spot and water lightly when the soil feels dry to the touch (probably once a day or every other day). Eventually, you’ll notice green sprouts appearing!

Separating the onion and repotting

Once leaves have appeared and have grown to about 6 inches tall, it’s ready to be separated into different onions and repotted! (the one in the images has grown much more than that before being separated).

You’ll want a slightly larger container for your onion to grow in for this next step so the onion has space to grow. Take the onion out of the container, remove any old onion layers (scales), and cut the root system between the sections of new growth – to separate into multiple onions.

peeling the onion layers off the growing onion
pulling the layers off of the onion as its growing
onion base cut and separated
The one bulb separated into 4 onions

Repot into one larger pot or a few pots to give them extra space to grow think about how big


Cut the leaves shorter once you’ve repotted your onion. This allows the energy to be utilized for growing the onion bulb rather than the length of the leaves. These shoots will also grow back, and there will be less of a strain on the onion! The green shoots can be eaten like you would green onion, although they do have a more mild flavor.

onions repotted with tops cut off

The leaves will naturally bend too which is fine! Continue to water the plant when it feels dry for a few months.

When the plant looks like it’s starting to die (some yellowing leaves), that’s when it’s almost ready to harvest! When some of the leaves start yellowing and bending (which will be at the end of summer if you planted them in spring), bend all of the leaves at the base to signal for the plants to go dormant. At this point, stop watering the onion, and don’t water for about 2 weeks.

Or wait a few weeks after it’s flowered.

onions flowering

If you keep watering now, it will rot because the plant has been told to go dormant and will not be using any more water. After the 2 weeks, it’s time to dig up your onion!

Growing onions in containers is a really easy way to grow your own food using just scraps! One of the best parts is that after this you can grow another onion from the onion you just grew.

Looking for other herbs to grow in containers? Find those here!

There will be more updates on how to dry and store these onions soon!

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You don't have to have a big garden to grow your own onions. All you need are an onion, a container, some dirt, and water!

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Looking for information specific to Colorado? Check out Naturalist Perspective!

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