How to grow green onion / scallion
Allium fistulosum / cepa · Amaryllidaceae · Vegetable
When to plant green onion / scallion: the short answer
Start seeds indoors about 8 weeks before your last spring frost; plant out about 4 weeks before it; sow outdoors about 4 weeks before the last frost; for a fall crop, sow about 8 weeks before your first fall frost. Seeds germinate in soil from 45 to 85°F, fastest near 70°F.
Cold winters (zone 5): plant out Mar 26 – Apr 12, or sow Jul 31 – Aug 17 for a fall crop. Mild winters (zone 9): sow Sep 25 – Oct 12 for fall and winter harvests; the spring window (Jan 16 – Feb 2) closes before the summer heat. Skip the hottest months for green onion / scallion. See every zone.
Green Onion / Scallion is a cool-season vegetable in the Amaryllidaceae family, grown either from a direct sowing or from transplants. It wants full sun, though it tolerates a little afternoon shade in hot regions and steady, even moisture. From sowing to first pick is about 60–80 days. It handles frost well and a light freeze often improves the flavour.
Grower’s note: Harvest any time from pencil-thick on - there is no wrong size. Re-grows from the trimmed root ends in water or soil. Shrugs off crowding, so sow thickly in a band.
Sowing
Sow about 0.5″ deep, into soil between 45–85°F — germination is quickest near 70°F. Germination takes a week or two (7–14 days). For an early crop, start seed indoors about 8 weeks before your last spring frost and grow it under bright light.
Spacing & layout
Give each plant about 1″ along the row with roughly 6″ between rows. On a square-foot grid that is 16 per square foot. Allow at least 8″ of loose, workable soil for the roots. It grows well in containers at least 6″ deep.
Fitting it to your season
As a cool-season crop, green onion / scallion does its best growing in the mild weather of spring and fall and tends to bolt or turn bitter in summer heat. A second sowing in late summer, timed to mature as the weather cools, is usually the better crop of the year — and light frost only sweetens it.
Quick facts
Growth stages: how long green onion / scallion takes to grow
From sowing to first harvest takes roughly 60-80 days (9-11 weeks), with seedlings appearing after 7-14 days in soil around 70°F.
When to plant green onion / scallion
When to plant green onion / scallion by USDA zone
Dates worked out from each zone’s typical frost dates for 2026. Find your zone on the zone map, or pick your state below for dates from its own frost dates. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Last / first frost | Start indoors | Sow or plant out | Fall or second sowing |
|---|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | Mar 13 – Mar 27 | Apr 10 – Apr 27 | Jul 11 – Jul 28 |
| Zone 4 | May 10 / Sep 25 | Mar 8 – Mar 22 | Apr 5 – Apr 22 | Jul 21 – Aug 7 |
| Zone 5 | Apr 30 / Oct 5 | Feb 26 – Mar 12 | Mar 26 – Apr 12 | Jul 31 – Aug 17 |
| Zone 6 | Apr 15 / Oct 15 | Feb 11 – Feb 25 | Mar 11 – Mar 28 | Aug 10 – Aug 27 |
| Zone 7 | Apr 5 / Oct 25 | Feb 1 – Feb 15 | Mar 1 – Mar 18 | Aug 20 – Sep 6 |
| Zone 8 | Mar 20 / Nov 5 | Jan 16 – Jan 30 | Feb 13 – Mar 2 | Aug 31 – Sep 17 |
| Zone 9 | Feb 20 / Nov 30 | Dec 19 – Jan 2 | Jan 16 – Feb 2 | Sep 25 – Oct 12 |
| Zone 10 | Jan 30 / Dec 15 | Nov 28 – Dec 12 | Dec 26 – Jan 12 | Oct 10 – Oct 27 |
Companions
Carrot, Beet, Lettuce, Tomato, Cabbage
Bush Bean, Pole Bean, Pea
Common problems
Pests: onion thrips, onion maggot.
Diseases & disorders: downy mildew, purple blotch.
Same family (Amaryllidaceae)
Rotate these so they don’t follow each other in the same bed year to year.
Questions gardeners ask
When should I plant green onion / scallion?
Start seeds indoors about 8 weeks before your last spring frost; plant out about 4 weeks before it; sow outdoors about 4 weeks before the last frost; for a fall crop, sow about 8 weeks before your first fall frost. Seeds germinate in soil from 45 to 85°F. The table on this page gives dates for each USDA zone, and the planting calendar gives dates for your own state or ZIP code.
How long does green onion / scallion take to grow?
About 60-80 days from sowing to the first harvest. Seeds germinate in 7-14 days, fastest in soil around 70°F.
How much sun does green onion / scallion need?
It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough.
What soil pH does green onion / scallion need?
A soil pH between 6.0 and 7.0. Test before adding lime or sulfur - see the soil pH and testing guide.
How far apart should I plant green onion / scallion?
Space plants about 1 inch apart in rows 6 inches apart, or 16 per square foot in a square-foot bed. Sow seeds about ½ inch deep.
Can I grow green onion / scallion in a container?
Yes. Use a container at least 6 inches deep with drainage holes and a good potting mix, and water more often than you would in the ground.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.