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How to Regrow a Sprouted Onion in Your Garden

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Wondering what to do with that sprouted onion in your produce basket? What if I could show you how to use it so you can plant and regrow a brand new onion in your garden?

Three onions that were grown in a 5-gallon bucket from onion sprouts

How to Plant a Sprouted Onion in Your Garden

Learn how to re-grow that sprouted onion into a brand new onion in this easy gardening tutorial.
4.65 from 28 votes
Prep Time: 10 minutes
Active Time: 30 minutes
Total Time: 40 minutes


  • Sprouted onion


  • Cutting Board
  • Knife
  • Small mixing bowl


  • Cut carefully into the onion lengthwise to expose the center sprout. Be careful not to cut through the root of the onion.
    Sprouted onion cut in half length-wise, exposing the sprout
  • Remove the outer layers of the onion, until you just have the center sprout remaining. As long as the outer layers of the onion are still firm, you can eat them. If they're soft, discard them. If there are multiple sprouts like this one, separate them.
    Onion sprout removed from sprouted onion on cutting board
  • Place the onion stem into a cup or bowl of water, and leave it there until roots start to sprout. These are the beginnings of roots. I like to leave them in the water until they're a bit longer before transplanting the onion sprout.
    Onion sprout with roots forming
  • Once you have roots developed, transplant the onion into the ground or a container full of good potting soil. I didn’t separate these ones, and they didn’t grow right. Take my lesson and separate all of the sprouts before planting.
    Onion sprout transplanted into potting soil in an orange 5-gallon bucket
  • Let them grow through the season. You can usually tell that the onion is done growing when you see the bulb emerge from the soil, or the green sprout starts to wilt and brown. If you leave them too long, they'll soften and rot. If you pull them at the right time, you'll have beautiful onions that you grew practically for free!


See Tips Below

Tips for how to grow a sprouted onion.

I started researching and tinkering and figured out how to plant sprouted onions in my garden to grow brand new onions. Over the years, I’ve also found that you can also cut the center out of onions that haven’t started fully sprouting and regrow them! * Just be very careful not to cut through the roots of the onion.

Of course, you can get some onion seeds and grow onions from seed, or go the super easy route and get onion sets from last season… but it’s so much fun to re-grow sprouted onions. The process to regrow a sprouted onion to plant in your garden is surprisingly simple.

How to re-grow sprouted Green Onions?

That’s a great question that is answered on my blog post:
How to Re-Grow Green Onions

Make sure the sprouted onion is not rotten.

Even if the onion is sprouting, if there are any black or rotten spots on the onion… just throw it away. If the layers of the onion are soft or a little mushy, but not rotten, you can use usually replant the sprout as long as it’s still firm.

How often should I change the water?

You should change the water the roots are growing in once every 24-36 hours. If you let it go much longer than that, the water stagnates and can cause the onion to rot.

Recycle water!!!

If you’re using non-chemical soap, shampoo, face wash and so on… your shower water runoff is also a great source of a little bit extra nutrients.

Keeping 2 5-gallon buckets in your shower and catching your shower runoff is a great way to water your garden plants.

When planting onions in a container…

It’s always important to make sure your soil has proper aeration.

Mixing in perlite, silica stones, small lava rock, small gravel, expanded clay pellets, coco coir or anything like that will help with drainage. This will help keep the soil from getting compacted which will help bring oxygen to the plant’s roots and help the plant grow bigger.

A great ratio of perlite is 20-30% perlite to the soil. This will give good drainage while not drying the soil out too fast. I recommend watering your onions every 2-4 days, depending on your soil drainage. Please do not overwater them… or they will rot.

When planting onions…

Regardless if they’re in the ground or in a container, you’ll want to make sure they’re 6-8″ from center apart. From my experience this allows the onions to have room to grow larger.

What type of onions?

White, yellow, red, Vidalia, sweet… it doesn’t really matter. It’s pretty much the same concept for all of them.

What time of the year do you plant onions?

If you plant your onions in containers, you can grow them year-round by taking them in and out of the house or even placing them near a sunny window if it’s too cold outside.

If you’re planting them outdoors, around 4-6 weeks before the last expected frost date (you can see 1st and last expected frosts in the different US zones on Morning Chores).

What time of the year do I plant all of my vegetables?

If you would like to learn what time of the year to plant all of your vegetables, I highly recommend Pam Farley’s Vegetable Garden Planting Schedules. It’s a must for every gardener!!!

Remember to save this Pin “How to Regrow a Sprouted Onion in Your Garden” to your Garden Board.

Three onions in a 5 gallon bucket that were grown from a sprouted onion

2 thoughts on “How to Regrow a Sprouted Onion in Your Garden”

  1. Do you know you can grow garlic. Only with a half of a globe. Plant it and it will grow a whole blub. I used to do it all the time.

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