How to Grow and Plant Onions from Onions - Backyard Boss
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How to Grow and Plant Onions from Onions

Looking for a simple and effective way to grow your own onions, then why not use onions?

Onions are one of the easiest vegetables to grow in your garden and require little effort from you. Even better, all you require to actually grow onions is… more onions! When you finish using up an onion for cooking, the bottom root is always leftover. Rather than tossing it into the compost or your disposal bins, reuse those onion bottoms to grow another onion. Here is everything to know about growing and planting onions from onions!

Materials Required

  • Knife
  • Onions (red, yellow, or white)
  • Jar or small bowl
  • Toothpicks
  • Gardening trowel
  • Gardening gloves
  • Soil, compost, and fertilizer

Step One – Choosing Onions to Regrow

Piles of red onions, white onions, and yellow onions on display
Image credits: Kelly Common via Unsplash

The type of onion you choose to grow is up to you! There are plenty of onion varieties that are available for purchase from grocery stores. Or you have the option to simply plant whatever onion is sitting around in your pantry. The most commonly grown varieties include yellow onions, red onions, and white onions. Whatever your preference, select the onion you want to grow and get ready to start planting!

Pro tip: Green onions are another type of onion that grow quickly from scraps! For more on growing green onions from other green onions, check out the article.

Step Two – Cut Off the Onion Root

Person in kitchen wearing apron, using kitchen knife to cut off bottom or onion
Image credits: Ronan Kruithof via Unsplash

Growing onions from onions is easy, and all it requires is the onion of your choice. Grab your onion and cut an inch and a half off the bottom of the onion (the part with dried roots). Store the rest of the onion in the fridge or use it right away. The sliced bottom is the only item required to plant your new onion!

Step Three – Preparing Your Onion for Planting

Once you have cut your onion root, allow it to dry, cut side facing upwards, for about a day. Now that your onion has dried out, use toothpicks and insert them into four separate places around the onion top. Next, fill up a bowl of water, and place your onion with its toothpick extensions over the bowl. The dried roots of your onion bottom should be immersed in the water. Place your bowl with the suspended onion in a sunny location for roughly three or four days. After this time frame, you will observe new roots beginning to sprout through the bottom of your onion!

Some gardeners prefer to skip this step and instead plant the dried onion bottom directly into the soil. Preparing the onion ahead of time is advantageous, as it offers early growth prior to planting it in the ground.

Step Four – Planting Your Onions

close up image of onion bulbs poking through the ground with tall green leaves above them
Image credits: Maarten van den Heuvel via Unsplash

Now that your onions are sprouting, it is time to plant them. The best time of year to plant onions is either in the spring (for summer harvesting) or early fall (for following spring harvesting).

The soil where you plant your sprouted onion bottom must include compost and fertilizer in it. Doing this encourages your onion plants to grow big and healthy. After you prepare your garden beds, make impressions in the dirt the size of your onion cutting (an inch and a half). Place your onions in these impressions with the roots facing down and cover the onion with soil.

If you are low on garden space, containers or pots are another great option for growing onions. Ensure the container you plant your onion in is eight to 10 inches deep. The width should also allow five inches between each onion for best results. On the other hand, if you are planting onions in the garden, you can plant as many as your space allows! Remember to give five inches between each onion, and if you have multiple rows, have 12-18 inches between rows.

Step Five – Care for Your Onion Plants

close up shot of multiple onions almost ready for harvesting in a garden
Image credits: Couleur via Pixabay

The key to growing healthy and big onions? Water!

Water your newly planted onion immediately after planting, making the soil damp (but not soaking!). Continue caring for your onion plants by regularly watering with about an inch each week. You can save on watering costs by harvesting rainwater or adding a natural mulch! Soon enough you will see onion shoots popping through the ground.


When it comes to growing vegetables from scraps, onions are an easy option to grow more onions. All you need to produce a fresh, homegrown onion is another onion from the grocery store or your pantry!

To grow your onions from onions, cut an inch and a half off the root section of your onion. Let this cut section dry in your home for about a day. Then, using toothpicks, insert them around the top of the onion. Suspend it over a bowl of water with the dried roots immersed in the water. Leave your onion to soak in the sun for three or four days and new roots will form!

Once the new roots have emerged, it is time to plant your growing onion in the ground. Plant it in the soil an inch and a half down with a mixture of compost and fertilizer. If planting multiple onions, give them five inches between one another, with rows 12-18 inches apart. Once your onion is planted, water the soil until it is damp. Continue watering your onion plants about an inch a week.

Growing onions from onions is a great way to use up all of your scraps in your kitchen and gain the reward of more onions. Happy planting!