How to Grow Scallion

Growing guide

Overview

Scallions, also called green onions, are the fastest and most forgiving crop you can grow. You sow a pinch of seed and start cutting fresh green tops in as little as 25 days, with full harvest by 45 days. They need full sun to partial shade, moderate water, and loose, well-drained soil — almost any sunny spot or a 1-gallon container works.

Soil & planting prep

Scallions grow best in loamy, well-drained soil rich in organic matter; they tolerate a wide pH range but prefer 6.0 to 7.0. Work in 2 to 3 inches of compost before planting. Sow seeds 1/4 to 1/2 inch deep, about 1/4 to 1/2 inch apart in rows 6 to 8 inches apart, then thin to 1 to 2 inches apart as you harvest.

When to plant

Direct sow scallion seeds outdoors as soon as the soil can be worked in spring — about 2 to 4 weeks before your last frost date, since scallions are frost-tolerant. For a steady supply, sow a new pinch every 2 to 3 weeks through late summer. In hot climates, fall plantings in late summer to early fall also work well.

How to plant

1. Choose a spot with full sun to partial shade and loose, well-drained soil; mix in 2 to 3 inches of compost.
2. Sow seeds 1/4 to 1/2 inch deep, scattering them thickly — about 1/4 to 1/2 inch apart — in rows 6 to 8 inches apart.
3. Water gently after sowing to settle the soil; keep the bed evenly moist until seedlings emerge, usually in 7 to 14 days.
4. Thin seedlings to 1 to 2 inches apart once they are 2 to 3 inches tall, using the thinnings as baby scallions.
5. Sow another small patch every 2 to 3 weeks for a continuous harvest through the season.

5 common mistakes to avoid

• Sowing too deeply — scallion seeds need light to germinate, so planting deeper than 1/2 inch causes poor or no sprouting; keep the seed barely covered.
• Letting the soil dry out completely during germination — the tiny seeds desiccate and die; water lightly every day or two until seedlings are up.
• Never thinning — crowded scallions stay pencil-thin and never size up; thin to 1 to 2 inches apart and eat the thinnings.
• Planting in heavy clay that crusts over — the seedlings can’t push through and the bulbs rot; always amend with compost for drainage.
• Harvesting only the green tops and yanking the whole plant too early — you get one small cut instead of a longer harvest; either pull whole plants when they reach 1/4 to 1/2 inch thick, or cut above the white base and let them regrow.

Harvesting & storage

Scallions are ready when the green tops are 6 to 8 inches tall and the white base is about 1/4 to 1/2 inch thick — usually 25 to 45 days from sowing. Pull the whole plant, or cut it about 1 inch above the soil line and it will regrow for a second cutting. Store washed scallions in a plastic bag in the refrigerator for up to a week, or stand them in a glass of water on the counter.

Companion planting

Scallions grow well with carrots, lettuce, and tomatoes — their scent helps repel some pests. Avoid planting them right next to beans or peas, as alliums can stunt legumes.

Growing in containers

Scallions are excellent in containers — use at least a 1-gallon pot with drainage holes and a loose potting mix. Sow thickly, keep the soil evenly moist, and harvest by pulling or cutting; a sunny balcony is perfect.

Pro tips

Direct sow thickly and thin as you harvest, or regrow from kitchen scraps in a glass of water. Succession-plant every 2-3 weeks for a continuous supply.