How to Regrow Green Onions from the Kitchen plus a little background on onion types
All my life, green onions from the garden have been a springtime thing. For me green onions, spring onions, and onions were just the same plant at different ages. We would plant a lot of onions really close together as soon as it was warm enough to go outside in short sleeves. Then, over the next several weeks, we would thin the onions by pulling some to eat as green onions. Later, when the onion bulb would begin to form and was about golf ball size or a little smaller, we would thin again. This second round were ‘spring’ onions. Finally, when the bulb was fully formed in the summer we would harvest the onions.
For the most part, this is correct. There are many varieties of onion to choose from when growing, such as Vidalia (technically only grown in Vidalia, Georgia, USA), 1015 sweets, red onions, yellow onions, and so on. And you can get green onions, spring onions or mature onions from any of them depending on when you harvest. But it turns out that is only half the story. There are actually, botanically speaking, two types of onion: bulbing onions (allium cepa) and bunching onions (allium fistulosum). All of the onions mentioned so far are bulbing onions, or A. cepa. Bunching onions, or A. fistulosum, look almost identical but doesn’t grow a large bulb. Commonly known as Welsh Onion (not because they are from Wales but from the German word for ‘foreign’), bunching onions are typically grown as perennials with leaves and flowers harvested for food or grown as decorative plants in the landscape.
Knowing that, it turns out the tip I’m about to share started with a misunderstanding. When originally shared with me, the method for regrowing green onions was based on the fact that the green onions purchased in grocery stores were bunching onions. While the tip still works as described, a little research indicates that in North America most of the green onions sold in stores are bulbing onions picked early. No matter, it still works.
Re-Growing Green Onions
- Cut off the botton inch or so or the green onions, leaving the roots intact. (Use the remainder of the onion for whatever delicious recipe you had in mind.)
- Place these cut ends in a glass or shallow bowl with enough water to cover the roots. After a few days, they will begin to resprout.
- Once the new sprouts are 2 to 4 inchines long, they can be replanted in the ground or a container. Be sure to pick a sunny location with well drained soil. (Our beds at Harvest Gardens are ideal!)
- To harvest, simply select a plant and cut the leaves off near the ground. The plant will respout and regrow new leaves rather quicly.
- Plants can be kept alive for quite a while. I had a couple dozen onions in a planter on my patio producing strongly for over a year until the infamous “Freeze of ‘;21” hit Texas this winter and finished them off.
Update (April 21, 2021): Here are the onions I restarted the same day I posted this tip…ready for harvesting as needed. And it turns out the onions I used (purchased at a local Aldi’s grocery) were indeed bunching onions, not bulbing. You can tell by looking at the profile of a cut leaf. Bunching onions will be flat on one side, forming a “D” shape.