I just love green onions and I eat them every chance I get. Two, they’re super easy to grow, even for beginner gardeners. Green onion plants readily seed themselves, returning to life every spring. But the main reason is that green onions, more than any other vegetable, have the greatest ability to regrow themselves. It’s truly amazing how these guys easily re-sprout from just the cut ends of store-bought bunches. In fact, all you need is a jar and some fresh water to get them going. It’s really easy to do. Let me show you how, as well as what to do with them after they sprout.
What Are Green Onions?
Green onions, also called scallions, are in that popular group of plants known as alliums. This is the same genus that includes regular onions, garlic, chives, and leeks. However, unlike its pungent cousins, green onions lack the developed bulb as the final harvest, instead growing long, tubular hollow green leaves. Delicious raw or cooked, because we’re growing green onions only for the leaves, they’re a much easier crop. We can forget about the biennial nature of these plants and just harvest the leaves over and over. Compounding this crop’s value, in fact, even in temperate gardens like mine with heavy snow during the winter, green onions will come back year after year with little to no intervention on my part. But more on that later. What we’re really here for today is to take these guys and turn them into more of these guys.
How To Regrow:
The process is super simple. Cut the stems off, leaving at least an inch of the wide end with those root tips. This is the part we need to regrow. The more you leave on, the faster and more successful this project goes. The only problem with that is the crunchy white parts are so delicious. I did an experiment a while ago, testing just how much of the root end you need to leave on a green onion to be successful in regrowing them. It had some very interesting results. Okay, once you cut off the root ends of your green onions with a clean knife or scissors, fill up some containers with regular tap water. The key to success with keeping these onion tips alive is to make sure they stay upright and don’t submerge the tops. If those tops go underwater for any length of time, they can and will rot. Remember, green onions are still a terrestrial plant, but it’s not a problem to accomplish this. Simply use a skinny container and only fill it with about half an inch of water. Set them aside anywhere in your home that has light and wait for the magic.
Aftercare:
Within a day, the inner rings of the onion begin to elongate and appear to grow. This is normal and good to see, but what we’re really after are the roots. Depending on your temperature, new roots will begin to appear in as little as two to three days. Now, your green onions are likely going to have little root nubs left on them from the commercial harvesting. Sometimes these guys regrow, which is great—a head start is nice. But if they don’t, let’s not worry about it. New white roots will form out of the base shortly. I like to change the water every two days, as submerged onions, even when growing, make for some funky water. Within a week for sure, you’ll start to see some new white roots forming. Here, I’ve highlighted the new root growth so you can see it. As with any plant cuttings for propagation purposes, new white roots are the signal for success. As well, the shoots are now going to start growing significantly. At this point, the shoots will grow about a third to a half inch per day, just in water. Green onions are awesome, and they’ll continue to grow in just water. You can actually even harvest these guys a couple more times, and they’ll continue to regrow. Amazing! After a while, a few things start to happen, however. The taste begins to get less and less flavorful, and the overall vigor of the plants begins to wane. Like all plants, they eventually need soil to grow. If you’re just treating this as a fun experiment to regrow some grocery store veggies, then you’ve succeeded. But if you want unlimited green onions going forward, then keep watching.
Planting:
Okay, if we’re going to be planting up our green onions in soil, you actually want to do it much earlier in the process, usually around three weeks or less after you place them in water. The reason is the roots actually begin to get quite soft and less able to adapt to terrestrial life. The root cap and the root apical meristem need to be strong enough to fight their way through the soil to anchor the plant and begin functioning as a true root system. The soft, mushy roots of a terrestrial plant left in water for too long are prone to rot and failure when they’re removed from their aquatic homes. There’s no specific timeline for when this actually happens, though, but I find that after a month or so in water, the time for these roots’ viability is becoming increasingly limited. And because we can root green onions by planting them directly in the soil with no water stage, no time is too early. However, the reason I don’t plant them right away is twofold. One, I’ve always hated to waste soil, so I want to make sure that I have a viable growing cutting before I plant it up. And two, the root collar where the stem meets the roots is quite low on green onions. It’s also where the soil line is going to be. Without an existing root system, it’ll be hard to hold the stalks in place unless you bury them deeper, which is not ideal. As for soil, any commercial potting mix will do. You want it to be light, airy, high in organic matter, and be good at holding moisture while still freely draining. To contain these guys, pretty much any size pot’s gonna work. With green onions, spacing doesn’t seem to be an issue, so any pot that’s at least four inches high with drainage holes should work just fine.
Alright, our green onion shoots have been growing for about two weeks now. Let’s go ahead and pot them up. The easiest way to do this is to fill up your container the whole way with that potting mix, right to the top, and pack it in nice and snug. Then, make your holes for the shoots—not too deep. Remember, you don’t really want to bury that root collar. Place the shoots in at the desired depth, pack the soil around it, and that’s it! Pretty straightforward planting. For watering, this is where it gets tricky. Established plants are easy to water. Once a week or so, usually less often, just water the soil like you would any other plant. But right after these guys are planted, you can’t do that. Watch what happens instead: One trick that I like to do is to water from below. Just soak the pot in a couple of inches of water overnight, and you’re good to go. The soil is going to soak up as much as it needs, as much as it can hold, nothing more, nothing less. Like all alliums, green onions need full sun for best results, but other than that, they’re quite undemanding, growing in adverse conditions just fine.
With the addition of potting these guys up, we just covered a lot of ground, probably a bit too much for such a simple process. So let’s recap, just hitting the main points:
Green onions are a biennial plant that have an extreme ability to keep growing even after being cut down and harvested. Just by taking regular grocery store scallions, cutting off the bottom inch or two, placing them in water, you can regrow another crop of those same green onions without much effort at all. They regrow fast at room temperatures, and you can cut them down and re-harvest them multiple times. As with any terrestrial plant, however, growing in just water, their health and vigor eventually start to deteriorate—they need soil. By planting your re-rooted green onions in standard potting soil, you can ensure that you’ll have an endless supply, never having to buy them at the grocery store again. Green onions are one of the easiest crops to keep happy; you don’t need a green thumb to grow an unlimited supply. No special tools, no expensive equipment, and no large amount of space required. If you’re looking to take your first step into the world of gardening or if you’re just looking for a fun project to do with kids, regrowing something that you probably already have in your fridge is an excellent idea. Happy growing, guys!
