I've been re-growing green onions from scraps on my window sill for about a year now, since I first saw on Pinterest that it could be done. I loooooooove green onions! It literally is not worth eating a baked potato without them for me, so I like to have them fresh and handy at all times. And the Dude is already demonstrating similar tastes, as they are one of his favorite things to eat straight! Cut up green onions? Dude is happy for 15 minutes in his high chair. Yup, he's my son. I'm so proud!
And I admit it, I'm cheap! I hate paying for stuff that I could get for free. Even onions that cost less then $1 at the grocery store.
There is definitely a knack to getting them to grow again, though, and I've learned a bit in the last year about coaxing them back into growth.
At first I had a kitchen with no windows, and I grew them behind the sink. You can imagine how well they did without sunlight! Yeah, not so well. So tip #1 is:
1. Make sure you put them someplace with sunlight. (Duh, I feel super silly now). And,
2. Make sure said spot is warm. In other words, don't put your onions right in your window in the dead of winter. (I'm also guilty of this one!) They won't grow if they're cold!
3. Use a clear glass, and make sure you keep water in the glass! I forgot to water mine for a few days and they shriveled up and turned brown in protest. Ditto when I put them in an opaque glass, apparently they really, really like the sun!
4. Make sure that the glass is big enough that the roots have room to grow. Eventually a tiny juice glass isn't going to cut it! The roots will get too long and tangled and start trapping mold between them, which makes the onions taste really, really, really bad (ugh, trust me on this one!).
The other problem with re-growing green onions from scraps is that they don't last forever if you simply put them in water alone. Eventually they stop growing, because even a hardy plant like green onions need the nutrients from the soil. Sun and water just don't cut it.
I've been continuously re-growing this crop for about six weeks, and I can tell that the growth is slowing down. They aren't coming back as quickly as they did at first, or as big. Not only that, but they were starting to get to the point where the roots were trapping mold, and I learned my lesson there! I will never make that mistake again, blech!
Luckily, this time I had this cute pot laying around, and the leftovers from the bag of potting soil and plant food from planting basil seeds with the girls:
I decided to try transplanting my almost-finished green onions into a pot, which I could hopefully keep in my window sill forever!
I just mixed in some plant food, gently separated the roots and spread out the onions so that they had some breathing room, and transplanted them into the pot. I made sure to pat the dirt down a bit to keep them in place, and tuck them in nicely. They got a cozy (warm) home on my kitchen window sill, and I left them to see if they would recover for me, poor babies!
A few days later, I had this!
So my final tip is to simply transplant them into a small pot if it's possible. They are a plant after all! A little dirt, sun and water should keep them producing for a long, long time!