Or more accurately, how to regrow green onions without dirt. A green onion is kinda like a lizard. You can pull off its tail, and a new one will grow right back.
I harvested all my green onions last month — and exactly 40 days later, I still have fresh green onions growing daily.
The trick? A glass of water and a sunny windowsill.
This is an easy project that shouldn’t even be called a project. You simply dunk a bunch of green onions in water, sit back, and watch the magic happen. You don’t even have to grow your own green onions in dirt first; store-bought onions work as well.
Just make sure the roots of your onions are intact. I’m lazy and don’t even rinse mine. They go straight from the garden to the glass. (Of course, rinsing the dirt off wouldn’t hurt either.)
Clip off the green parts to cook with, but leave a few inches at the bottom to regrow. There’s no exact science to this — as long as the roots, whites, and a little bit of the greens are still there, your onions will grow again. (You can actually get away with leaving just the last inch above the roots, but it will grow back much, much slower.)
Fill your glass with enough water to cover the roots and then some. You don’t need full sun to regrow onions, but a sunny windowsill does speed along the process. It also helps to change the water every few days to keep things fresh.
After a week, this is what my green onions looked like.
I’ve cut them back several times by now, and they still keep going with no change in flavor that I can taste. The green tops sprout from the bulb in just a few days’ time, so you can have a steady supply of green onions for at least a month — or more. I wonder if I can keep mine growing through the summer!
Now I know what you might be thinking… why bother? Green onions are cheap, and you like to use the white part anyway. Personally, I rarely use more than a few stalks for garnishing and I’ve composted many a bunch gone bad. Green onions are one of those kitchen staples that often end up slimy and forgotten in the fridge. So when I harvest or buy a bunch, I’ll use half and regrow half. I still get the bulbs, and I save the rest from spoiling!
Jodie BjolaAugust 6, 2021 at 4:32 pm
I started replanting the ends of my store bought green onions a few years ago and it worked well. This year I just cut off same plants while still in the ground, leaving at least a 1/2 inch for it to regrow over and over again.
FylApril 10, 2015 at 9:02 am
wonder if you can get the green tops to root and clone a new bulb in aero/hydro, too?
Linda LyApril 13, 2015 at 12:47 am
I am currently not familiar with that method.
eljunzFebruary 16, 2015 at 12:13 am
I never thought this can work? I’m tired of growing green onions outside they just can’t last long. I’m gonna try this new trick, thanks!!!
Linda LyFebruary 22, 2015 at 7:19 pm
You’re welcome! Enjoy!
eljunzMay 4, 2015 at 8:53 pm
Yep, it does work however I got tired in replacing the water every other day so I decided to move them in the soil….haha
LeahOctober 19, 2013 at 5:24 pm
That is so cool! I wonder if it would work with Cilantro? I live in Fiji and have just come across your blog, find it really useful even for the tropics 🙂
Linda LyOctober 21, 2013 at 8:39 pm
As for cilantro, they’ll probably grow new leaves if you put them in water with the roots attached, but they’ll grow sloooowly and need to be transferred to soil. However, I do keep harvested cilantro in a glass (or small vase) full of water to keep them fresher longer.
OniMay 18, 2012 at 11:20 pm
Hi ~ just want to let you know I have been regrowing my green onions since March 10 (i know the date because I started when I got back home from visiting my husband) I mostly clip the ends and store them in an old mayonnaise container in the freezer til i’m ready to use, but I just took another 22 day vacation – when I got back last week, my onion nubs had grown almost 3 feet! i have 7 onions that I bought from the grocery store. I try to change the water (though i didn’t for the past 22 days) and rinse the goo off of the roots (and trim the roots if they grew too long) once a week or so, and they are still going strong! I sometimes add a pinch of sugar and a pinch of rock salt to the water when I remember, though i’m sure that plants MUST need more nourishment than that….
Linda LyMay 22, 2012 at 2:00 pm
What a sight to come home to 3-foot-tall onions! Hope they’ll keep on growing through the summer!
oukayMay 18, 2012 at 9:57 am
I have some in the refrig right now trying to go slimey. Maybe I can rescue them!
Linda LyMay 18, 2012 at 3:02 pm
You can keep other herbs fresh this way too. I usually keep parsley or basil in water until I use them all up.
PJOctober 19, 2014 at 1:21 pm
chop and dry them in a dehydrator!
Maryf AllenMay 18, 2012 at 7:36 am
Great idea. I’ll try this.