Green onions, also commonly called scallions or spring onions, are versatile for a wide variety of dishes, and they are easy to grow. In fact, they're so effortless that there are several good methods for how to grow green onions that work whether you have an outdoor garden or an indoor space.
Regrow Green Onions From Cuttings
By far, the easiest way to grow scallions is to regrow them from cuttings. As long as you have a root end, you can regrow green onions. When you purchase them from the grocery store, green onions always have the root end attached because they stay fresher and last longer with the root in place. When cooking with scallions, people always cut off the root end. But, if you keep it rather than composting it, you can regrow your own green onions. You'll need a one to two-inch portion of stem and roots for best results.
To regrow green onions:
- Place the root ends of green onions root-side down in a shallow glass or jar.
- Add just enough water to cover the roots.
- Place the container in a bright, sunny spot.
- Change the water every few days to keep it fresh, and check regularly to make sure that the roots are still submerged.
- In just a few days, you'll see new green growth appearing.
- After this point, you can harvest regularly as long as the root end stays healthy and continues supporting new growth.
- If you notice that, after a week or so, no new growth is appearing, it might be a good idea to compost the root and try with another one.
While the green onion can grow in water for a few weeks, if you'd like to keep them going longer than that, it's a good idea to plant them in some soil.
- Plant them out in a garden bed or in a container with some potting soil.
- Plant an inch to an inch and a half deep, firm the soil gently around them, and water. They'll continue producing all season long, and possibly even longer.
How to Grow Green Onions Outdoors From Seed
It's also easy to grow green onions from seeds. Start them indoors under lights and then transplant them, or sow them directly into the garden after your last frost date.
To plant green onion seeds in your garden:
- Plant about a quarter of an inch deep and two inches apart.
- Green onions grow best in loose, fertile, well-drained soil in a spot with full sun.
- They will take a bit of shade, but they won't grow as robustly.
- The trickiest part with starting green onions from seed is that they germinate somewhat slowly, taking as long as 14 days, and the soil needs to be kept evenly moist the entire time.
- Once they've sprouted, water regularly and keep the area weeded.
They'll grow best when fertilized monthly with a balanced fertilizer. Harvest as often as needed once they reach about eight inches tall, and they'll continue to sprout as long as the roots are healthy.
Grow Scallions From Seed in Containers
Green onions grow well indoors in a bright, sunny window or under grow lights. Any container will work, as long as it is at least six inches deep. In their classic container gardening book, The Bountiful Container, garden writers Rose Marie Nichols McGee and Maggie Stuckey note that if you want scallions or green onions with more white than green, you can blanch them, which simply means mounding soil up higher along the stalk to deprive that part of it of sunlight. This will keep it pale rather than dark green. You can easily do this in both containers and in garden beds, but it isn't necessary unless you have a strong preference for the milder-tasting white parts over the stronger-tasting green.
- In a container, space the seeds two inches apart in well-drained potting soil, and keep them evenly moist.
- Place the container outdoors all season, and then bring it indoors before your first fall frost so you can continue to grow green onions throughout the fall and winter.
Try Succession Planting
If you'd like a steady supply of green onions, sow a new row or container every two weeks through the spring and early summer. This will ensure that even if you harvest a large number of them from one sowing, you'll have others growing steadily that will be ready to harvest soon as well.
Overwinter Green Onions
It isn't difficult to overwinter green onions in the garden, especially if you live in a place that has mild winters. To overwinter them:
- Cover onions after your last frost date with a mound of fallen leaves or straw.
- In the spring, rake it back, and your green onions will start growing again.
- Most likely, sometime in early summer, they'll send up a flower stalk. You can remove that to keep the plant producing longer, or you can let it bloom - the flowers are edible, as well, and are a pretty addition to salads or egg dishes.
Growing Green Onions Is Easy
Whether you have a full garden bed, a patio container garden, or a windowsill garden, you can grow green onions. Even better, it's easy to grow them from something you'd usually toss into the compost. As long as the root of a green onion is left intact and given water and occasional fertilizer, it will continue growing for months, regrowing when the tops are harvested. With that in mind, it's definitely worth growing some in your garden or on your windowsill.