How to grow green onion / scallion

Allium fistulosum / cepa · Amaryllidaceae · Vegetable

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

When to plant green onion / scallion

Companions

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.

Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.