Green onions are versatile members of the Allium family, harvested before their bulb fully develops. They feature long, slender green stalks that transition to a small white base. Both the green tops and the white bases are edible, offering a mild, fresh onion flavor. Their delicate taste and crisp texture make them a popular ingredient in various dishes worldwide.
Popular Green Onion Varieties
The terms “green onion,” “scallion,” and “spring onion” are often used interchangeably, though they refer to slightly different forms or stages of development within the Allium genus. Scallions, frequently called green onions, are typically Allium cepa or Allium fistulosum harvested young, before a significant bulb forms. They have a straight, slender white base and hollow green leaves, providing a mild onion flavor palatable raw or cooked.
Welsh onions, or Allium fistulosum, are distinct because they are perennial and do not form a true bulb, even when mature. They grow in clumps with long, hollow green stems and have a mild, sweet onion flavor. This variety is known for its ability to regrow after being cut, making it a sustainable choice for home gardens.
Spring onions are young onions, usually Allium cepa, harvested when a small, undeveloped bulb has begun to form at the base. This slight bulbing distinguishes them from scallions, and they tend to have a slightly more robust flavor. Their flavor is sweet and mild.
Japanese bunching onions, often referred to as Negi, are a type of Welsh onion (Allium fistulosum) known for their longer, thicker white shafts and a more pronounced onion flavor. These are particularly prominent in Asian cuisine, where their robust taste and texture are highly valued.
Selecting and Culinary Uses
When selecting green onions, look for firm white bases and vibrant green tops. Avoid any bunches with wilting, yellowing leaves or a slimy appearance, as these indicate declining freshness. The presence of healthy roots at the base is also a good indicator of freshness.
Before use, trim the root ends and rinse the stalks under cool running water. Both the white and green parts are edible. The white part has a more intense, onion-like taste, while the green tops offer a milder, fresher, and slightly grassy flavor.
Scallions and the green tops of other varieties are often sliced thinly and used raw as a garnish for dishes like stir-fries, soups, salads, and baked potatoes. The white parts, with their stronger flavor, are suitable for cooking applications such as sautéing, grilling, or roasting. Welsh onions, with their mild sweetness, are versatile for both raw and cooked preparations, commonly found in Asian dishes like miso soup or stir-fries. Spring onions, with their small, sweet bulbs, can be roasted whole to bring out their sweetness, or chopped and added to omelets.
Cultivating Green Onion Varieties
Green onions are adaptable plants that thrive in full sun, requiring at least six to eight hours of direct light daily. They prefer well-draining, fertile soil with a slightly acidic to neutral pH, ideally amended with organic matter like compost. Optimal growing temperatures generally range between 68 and 78 degrees Fahrenheit.
Green onions can be grown from seeds, sets (small bulbs), or by regrowing from the root ends of store-bought onions. When planting seeds, sow them about 1/4 inch deep and keep the soil consistently moist for germination, which typically takes one to two weeks. For continuous harvests, new crops can be succession-planted every three to four weeks. Regrowing from scraps involves placing the root ends, with about an inch of the white part, in a shallow jar of water on a sunny windowsill. Once new shoots appear, the regrown scraps can be transplanted into soil for sustained growth.
Regular watering is important, especially during dry periods, as green onions are shallow-rooted and require consistent moisture to prevent bolting. While generally hardy, ensuring good air circulation and drainage helps prevent issues like mildew. Welsh onions, being perennial, can be left in the ground year after year and will form larger clumps over time, which can be divided for propagation. Harvesting for continuous production involves cutting the green leaves as needed, leaving a few inches of the plant to regrow.