Welsh Onion

Seed can be direct-sown from early spring through mid-summer, or in July–August for a fall and overwintering crop, germinating between 46 and 86°F with best results above 60°F; it goes 1/4–1/2 inch deep in narrow 2–3 inch bands, spaced about 1/4 inch apart, and is thinned only if a larger-diameter stalk is wanted.

For transplants, 6–8 seeds are sown per cell and the resulting clusters are set out 6–8 inches apart in rows 18 inches apart; for negi-style plants with a longer blanched shank, seedlings are grown on in flats until pencil-thick, then transplanted into dibbled holes about 6 inches deep with only 1–2 inches of leaf left above the soil, left unfirmed so irrigation settles the hole naturally.

The crop favors a soil pH of roughly 6.2–6.8, though organic soils can run somewhat lower at 5.3–6.0, and responds to 50–70 pounds of nitrogen per acre worked in before sowing or transplanting, with a further side-dressing as the crop grows to keep the tops green. Hilling the base with soil two or three times through the season blanches and lengthens the edible stalk.

Grown as a perennial, the plant forms clumps that multiply on their own each year; plugs are typically set 4–6 inches apart, and a dense mulch of shredded leaves or sawdust helps suppress weeds in the resulting tight stand.

Pink root and botrytis leaf blight are diseases known to affect bunching onion plantings, and growers commonly start with fungicide-treated seed to guard against early disease pressure.

Clumps are loosened with a fork or underminer, gathered by hand, then washed and hydrocooled before being held near freezing until shipped or displayed. Because a perennial clump can multiply two- to five-fold each year, regular harvesting is needed to keep the planting from crowding into smaller bulbs and leaves; the earliest pickings in spring are tender scallion-type greens alongside overwintered bulbs with a sweetened, creamy texture.

Culinary: Welsh onion is an ingredient across East Asian cooking, especially in China, Japan, Taiwan and Korea, appearing in scallion pancakes, as a garnish for dishes such as Peking duck, and mixed into dumplings and meatballs; in Japan it is known as negi. In Western kitchens it is used more simply, mainly as a scallion or salad onion.

Ornamental: The plant is also grown in bunches as an ornamental, its tightly packed, spherical flowerheads drawing comparison to cottage-garden blooms.

Welsh onion was domesticated in the vicinity of Lake Baikal in Siberia, near the Altai Mountains, and in western or north-western China, a region where a wild relative, Allium altaicum, is still found today. The earliest written record of the crop dates to the first century BC, and it spread from Siberia to Japan during the eighth century AD; medieval traders later carried it from Russia into Europe. It remains especially popular in central Russia and Siberia, and has since become widely cultivated from Siberia to tropical Asia.