Green onions, also called scallions, are one of the easiest vegetables to grow. They take little space, tolerate cool weather and can be picked just three weeks after sowing as thin shoots, or left to grow into full-size stalks. They also regrow from kitchen scraps. This page covers when to plant, spacing, care, common problems and how to harvest green onions so you always have some on hand.
Green Onions at a glance
| Type | Vegetable |
|---|---|
| Season | Cool-season |
| Sun | Full sun |
| Plant spacing | 2 in |
| Row spacing | 12 in |
| Per square foot | 16 |
| Seed depth | ¼ in |
| Days to maturity | 60–80 from seed |
| How to start | Green onions grow best in cool weather, roughly 55 to 75°F, and handle light frost. |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant green onions
Green onions grow best in cool weather, roughly 55 to 75°F, and handle light frost. Sow seed outdoors about 4 weeks before your last spring frost, and keep sowing a short row every 3 weeks through spring. Sow again in late summer for a fall harvest. In mild-winter climates you can grow them all winter.
Look up your dates with the frost dates by ZIP code tool and plan repeat sowings in the planting calendar.
How to plant green onions
- Prepare the bed. Choose full sun and loose, well-drained, fertile soil with a pH of about 6.0 to 7.0. Remove stones and weeds, since seedlings are slim and easily crowded.
- Sow shallow. Plant seeds about a quarter inch deep in rows 12 inches apart. Seeds sprout in 7 to 14 days.
- Thin lightly. Thin to about 2 inches apart for thick stalks, or leave them close for thin shoots.
- Regrow scraps. Place the white root ends with roots attached in water or soil, and new green tops grow in a week.
Caring for green onions
Green onions have shallow roots, so give them about an inch of water a week and do not let the soil dry out. Use the garden watering calculator to convert that to gallons for your bed. Mulch lightly to hold moisture and suppress weeds.
Weed by hand and avoid deep cultivation near the roots. Feed once with compost or a nitrogen-rich fertilizer when plants are 4 to 6 inches tall. For longer white stems, mound soil around the base as they grow.
Companion plants
| Grow nearby | Carrots, beets, lettuce, strawberries and tomatoes |
|---|---|
| Keep apart | Peas and beans (said to stunt each other) |
Onions are said to help deter carrot flies and some other pests when planted nearby, and they take little space between larger crops. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Onion thrips | Silvery streaks on leaves | Spray with water, use insecticidal soap and keep plants watered during hot, dry weather. |
| Onion maggots | Wilting plants, hollow white bulbs | Use row cover and rotate planting spots each year. See the pest identifier. |
| Bolting | A flower stalk forms in the center | Caused by temperature swings. Pick the plant and use it, then resow. |
| Damping off | Seedlings collapse at the soil | Sow in well-drained soil and avoid overwatering. |
| Yellow tips | Leaf tips turn yellow | Often dry soil or low nitrogen. Water evenly and feed lightly. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see.
When and how to harvest
Pick green onions when the tops are 6 to 8 inches tall, usually 60 to 80 days after sowing and as little as 20 to 30 days for baby scallions. Loosen the soil, pull the whole plant, then trim off the roots. For repeat harvests, cut the green tops an inch above the soil and let them regrow.
Use the whites and greens raw in salads, or in stir-fries and soups. Store them in the refrigerator for 1 to 2 weeks, or stand the roots in a jar of water on the counter and they keep growing.
Plan your green onions
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant green onions?
Space green onions 2 inches apart in rows 12 inches apart. In a square foot garden, plant 16 per square foot.
How deep do I plant green onion seeds?
Sow green onion seeds about a quarter inch deep and thin to 2 inches apart.
How long do green onions take to grow?
Baby green onions are ready in about 20 to 30 days, and full-size stalks in 60 to 80 days after sowing.
How much water do green onions need?
About 1 inch of water a week, from rain and watering combined. Keep the shallow roots evenly moist.
Can you regrow green onions in water?
Yes. Place the white root ends in a jar with an inch of water in a bright window and new green tops grow in about a week. Change the water every few days, and replant in soil for better long-term growth.
Are green onions the same as scallions?
In most cases, yes. Both names describe onions harvested before a large bulb forms, though some people call the ones with a slightly swollen base spring onions.