Growing Green Onions from Scraps
By now, we all know there is a food waste problem. And I'm sure you have bought green onions for a recipe and had the extra onions go bad in the refrigerator. The easiest way around this waste is to grow green onions in your garden or windowsill year round. While you can buy seeds and grow green onions from start to finish, it is quicker to take the onion butts with roots still attached and grow them on. You may have heard you can grow green onions on in a cup of water, and though this is true to a point, the onions will eventually run out of nutrients. Growing the onions back in soil for a cut-and-come-again green onion, will give you tasty onions for up to a year rather than only a week or two.
How to Regrow Green Onions
Once you have cut off the tops of the green onions for cooking, place them in a glass or jar of water and place in a windowsill for 4-7 days. This will allow the roots to rehydrate and start to grow back. At that point, you will notice the green part will continue to grow at the same time the roots are as well. (Note: Ideally you do not want the roots grow longer than 1" or they will be more difficult to plant).
2. I forgot about my onions for about a week and a half and the roots got a little long, but it is okay. You will also notice at this point that the outer layer or two of the onion will be drying out and papery. You can remove this part now, but it is not required.
3. Use a pencil or chopstick to create a hole in your moist potting soil. Start by sticking it into the soil about 2" and rotate it around to make the hole large enough for the roots.
4. If you roots got a tad long, like mine, you can use the pencil or chopstick to help tuck the roots into the soil.
5. Continue planting up the rest of your onions trying to space them out at least 1.5" to 2" or the roots will not have enough room.
6. To give the onions an even better chance of thriving, it helps to cut them back to about 2" tall. This will allow them to not be top heavy while the roots have time to start anchoring them in the soil. Water lightly and place in a sunny window or patio.