I never planned to become the person who always has fresh spring onions on hand. Honestly? I used to buy them, use half, and watch the rest wilt in the fridge. That changed the day I figured out how to grow spring onion at home with almost no effort. Now I snip what I need straight from a pot on my windowsill or a small patch outside. The flavor hits different. Sharper. Fresher. And I waste way less.
This is not some complicated garden project. I keep it basic because that is what works for me. If you have a sunny spot, a bit of soil or even a jar of water, you can do this too. I will walk you through everything I actually do, the mistakes I made, and the little tweaks that finally made it reliable.
Why I Keep Growing These Tiny Alliums
Spring onions (also called scallions or salad onions) give me quick wins. They grow fast. They take almost no space. And they keep producing if I treat them right.
I used to think only people with big yards could grow real food. See, that was the wrong way to go about it. Space is not the real question. Consistency is. Once I stopped overthinking and just planted a few, the harvests kept coming. I use them in nearly everything: scrambled eggs, stir-fries, salads, baked potatoes. Having them ready means I cook more and order takeout less.
They also handle a surprising range of conditions. Full sun is best, but mine tolerate some shade. Shallow roots mean containers work great. And the regrow-from-scraps method feels almost like cheating.
Choosing Your Starting Point: Seeds, Sets, or Scraps
I have tried all three. Each has its place.
From seeds gives me the most plants for the least money. I sow them every few weeks for a steady supply. They take longer to reach harvest size, usually eight to twelve weeks, but the process feels satisfying.
From sets (small immature bulbs) gets me greens faster. I plant them and often harvest in three to four weeks. They cost more up front but skip the slow germination stage.
From kitchen scraps is my current favorite for indoor growing. I buy a bunch at the store, use the tops, and stick the rooted bottoms in water or soil. New greens appear in days. I have repeated this cycle several times from the same roots before they thin out.
Honestly? Start with scraps if you want results this week. Move to seeds once you get hooked.
How I Regrow Spring Onion at Home From Scraps
This method converted me. No special tools. No waiting for seed packets.
- Grab a bunch of store-bought spring onions that still have roots attached.
- Cut the green tops about two to three centimeters above the white base. Use the tops for cooking right away.
- Place the rooted ends in a small jar with just enough water to cover the roots. Keep the cut tops above the water line.
- Set the jar on a sunny windowsill. Change the water every two or three days so it stays clear.
- Watch new green shoots push up in three to five days. When they reach six to eight centimeters, I either keep snipping or transplant into soil for stronger plants.
I have also planted the bases straight into potting mix. Bury the roots and white part so only a little of the cut stem shows. Water lightly. Same sunny spot. This version lasts longer than pure water culture because the roots can pull nutrients from the soil.
The plants eventually run out of steam after three or four harvests. That is normal. I just start a new batch from the next grocery run.
Soil, Light, and Containers That Actually Work for Me
Spring onions are not fussy, but they do have preferences I learned the hard way.
They want well-draining soil rich in organic matter. I mix regular potting soil with a handful of compost. The pH should sit between 6.0 and 7.0. I do not test every time. If the mix feels light and drains after watering, I call it good.
Light matters more than I first realized. Aim for at least six hours of sun. My indoor pots sit on a south-facing sill. Outdoor ones get full morning light. Too little light and the greens stretch thin and pale.
Containers are perfect for this crop. I use anything with drainage holes that is at least fifteen centimeters deep. Old yogurt tubs, window boxes, or a simple fifteen-centimeter pot all work. For outdoor beds I just tuck them into gaps between other plants because their roots stay shallow.
One tip that saved me: never let the soil stay soggy. Rot is the main killer I have seen. Drainage holes and a light hand with the watering can prevent most problems.
Planting Spring Onions the Way I Do It Now
Here is the exact process I follow outdoors or in larger pots.
For seeds:
- Rake the soil smooth and remove stones.
- Make shallow drills about one centimeter deep and ten to twenty centimeters apart.
- Sow seeds thinly. I aim for a seed every two to three centimeters.
- Cover lightly, firm the soil with my hand, and water gently.
- Thin later to about five centimeters apart if they come up thick. The thinnings go straight into dinner.
For sets:
- Plant the pointed end up, about two centimeters deep.
- Space them four to six centimeters apart.
- Water in and keep the soil moist until shoots appear.
I succession sow every three to four weeks from early spring through late summer. That single habit keeps me in greens almost year-round in my climate. In colder spots I start some indoors in modules during late winter and transplant when the soil warms.
Indoor seed starting is simple too. Fill small cells with seed mix, sow a few seeds per cell, keep moist and warm (around fifteen degrees Celsius), and give them light as soon as they sprout. Transplant when the seedlings look sturdy.
Day-to-Day Care That Keeps Them Happy
These plants need surprisingly little once established.
Water is the big one. I aim for about two and a half centimeters of water per week, more in hot dry weather or for pots. Stick a finger in the soil. If the top inch feels dry, water. Consistency beats heavy soaking followed by drought.
I feed lightly. A diluted liquid fertilizer every few weeks during active growth is enough. Too much nitrogen makes lots of floppy leaves and less flavor, in my experience.
Weeds compete hard with these shallow-rooted plants. I pull them by hand early. Mulch with a thin layer of straw or dried grass once the seedlings are a few centimeters tall. It holds moisture and keeps weeds down.
Pests show up sometimes. Slugs love young seedlings. I check at night and pick them off, or use a simple barrier. Onion thrips or leaf miners appear in warmer weather. I have used insecticidal soap a couple of times with good results. Row covers help if you want to be proactive.
Diseases stay rare if drainage is good. I remove any plant that looks diseased right away and avoid watering the leaves late in the day.
Harvesting Without Killing the Supply
I start snipping when the greens reach fifteen centimeters or so. For full plants I gently loosen the soil and pull the whole thing when the white base is about the thickness of a pencil. Young and mild tastes best to me. Larger ones get stronger.
If I want the plant to keep producing, I cut the greens a couple of centimeters above the soil or water line and leave the base in place. New shoots push up again. This works especially well with the scrap method.
One season I left a few plants to bolt and form seed heads. I collected the dry seeds in a paper bag and saved them for the next year. Free plants. Always a win.
Common Mistakes I Made So You Do Not Have To
I overwatered the first pots and watched the bases turn mushy. Lesson learned: less is more once they are established.
I planted too deep with seeds and germination suffered. Now I keep coverage light, about half a centimeter.
I ignored succession planting and had a glut followed by nothing. Sowing small batches every few weeks fixed that completely.
I also tried growing them in pure shade once. The result was pale, leggy stems that tasted bland. Sun makes a clear difference.
Frequently Asked Questions
How long does it take to grow spring onion at home from seed?
Most varieties reach usable size in eight to twelve weeks. Sets and scraps give you greens much sooner, often in two to four weeks.
Can I grow spring onions indoors year-round?
Yes. A bright windowsill or simple grow light works. Keep the soil moist but not wet, and rotate the pot so growth stays even.
Do spring onions need fertilizer?
They appreciate a light feed every few weeks, but rich compost mixed into the soil at planting often covers their needs. I skip it sometimes and still get decent harvests.
Why are my spring onions flowering?
They bolt when stressed by heat, drought, or long days. Pull them for the kitchen as soon as you see flower buds. The flavor starts to change once they go to seed.
How many times can I regrow from the same scraps?
Usually three or four harvests before the bases weaken. Start a fresh batch from new store-bought ones when growth slows.
Final Thoughts From My Windowsill
Growing these little onions taught me that food production does not have to be dramatic. Small, repeatable actions beat ambitious plans that never start. I still buy other produce, of course. But the spring onions? Those stay free and fresh most of the year now.
Grab a bunch from the store this week. Save the roots. Stick them in a jar. Watch what happens. Once you taste the first homegrown snip, you will understand why I keep doing this. It is simple. It works. And it feels good every single time I walk over and cut what I need.