Scallion

Scallion (Allium fistulosum) is the true bunching onion - it does not form a bulb, it is harvested entirely for its green tops and slender white base, and it will regrow from the cut base for two to three additional harvests. A $2.49 seed packet planted in succession every three weeks keeps you in green onions from spring through late fall. If you’ve been buying bunches at $1.50 each, that adds up faster than you think.

What you’re actually growing

The common name “scallion” is applied loosely to several things. True scallion is Allium fistulosum, the Japanese bunching onion - it forms hollow cylindrical leaves and a small white pseudostem but never a distinct bulb. What you see in grocery store bins labeled “green onions” is sometimes A. fistulosum, sometimes immature bulbing onion (A. cepa) harvested before bulb development. They look similar but A. fistulosum is more cold-tolerant, perennializes in zones 6+, and regrows more reliably after cutting.

Standard varieties include ‘Evergreen Hardy White,’ ‘Red Beard,’ and ‘Parade.’ Some Asian varieties (‘Tokyo Long White,’ ‘Ishikura’) produce longer, thicker white shanks - these command a slight premium at farmers markets.

The ROI case

A $2.49 packet seeds 5-10 row feet. Harvest begins 60-70 days after germination. One row foot at standard spacing (1 inch between plants) holds 12 plants, and a bunch of 6-8 scallions weighs about 2 oz at the grocery store. That’s 24-32 oz, or 1.5-2 lb per row foot over the season with cut-and-come-again management.

At $3-5/lb retail (USDA AMS Specialty Crop Market News, 2023), a 5-foot row returns $22-50 in gross value through the growing season. The per-harvest value is modest but the cumulative return across multiple cuts is substantial relative to the input cost.

The kitchen scrap regrowth method is worth understanding: when you trim a bunch of store-bought scallions, the root end (1-2 inches with intact roots) will regrow to harvest size in 10-14 days when placed in a glass of water or planted in potting mix. This gives you one additional harvest from a $1.50 grocery store purchase. Repeated cycles are possible, though plant vigor declines after 3-4 cuttings.

Growing requirements

Scallions germinate well in cool soil (45-85°F) and grow best in cool weather. They tolerate light frost and can be planted 4-6 weeks before last frost in spring. In zones 6+, fall-planted scallions overwinter and resume growth early in spring.

Direct sow 0.25 inches deep in well-prepared soil. Thin to 1-2 inches between plants. Close spacing is fine - scallions are harvested before they need much lateral room.

Soil pH 6.0-7.0. Scallions are light feeders. Moderate compost amendment before planting is sufficient; additional fertilization is rarely needed for a 60-70 day crop.

Four to six hours of direct sun produces acceptable yields. Full sun (8 hours) produces faster growth and thicker shanks but is not required. This partial-shade tolerance makes scallions useful in spots unsuitable for most vegetables.

Keep evenly moist. Dry conditions produce thinner, stronger-flavored shanks; excess moisture causes the base to rot at the soil line.

What goes wrong

Onion maggot (Delia antiqua) is the most damaging scallion pest in the Northeast and Upper Midwest. Larvae tunnel into the base of the plant, causing yellowing and collapse. Adult flies emerge in spring and are attracted to fresh allium plantings. Row cover placed at planting and left in place through the season prevents egg-laying. There is no organic treatment once larvae are inside the plant - remove and discard affected plants.

Downy mildew (Peronospora destructor) produces pale spots on leaves with grayish sporulation visible in humid conditions. Remove affected leaves and improve airflow. Copper fungicide provides preventive protection in high-pressure seasons.

Pink root (Phoma terrestris, same as described for onion and shallot) produces pink, shrunken roots. Rotate alliums out of affected beds for 4+ years.

Scallion beds become weedy quickly because of the upright, non-competitive growth habit. Mulching between rows after germination suppresses most competition.

Harvest and storage

Cut the entire plant at soil level when the green tops reach 12-14 inches tall and the white base is 0.5-1 inch in diameter. Alternatively, cut 2-3 inches above soil level and allow regrowth - this cut-and-come-again method yields two or three additional harvests from the same root, though each successive harvest produces thinner tops.

Fresh-cut scallions last 7-10 days refrigerated, wrapped loosely in a damp paper towel inside a plastic bag. For longer storage, chop and freeze in a single layer on a sheet pan before transferring to bags. Frozen scallions lose their texture but retain flavor for cooked applications for up to 6 months.

Do not store scallions at room temperature - they yellow and wilt within 2 days.

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Related crops: Carrot, Garlic

Related reading: Companion Planting Basics - alliums as pest confusers near carrot - what the evidence actually shows