Scallions, often referred to as green onions or bunching onions, are the slender, non-bulbing members of the Allium family (Allium fistulosum). These plants offer a mild, fresh onion flavor from the white base up through the hollow green stalks. Growing them from seed, rather than using store-bought sets or transplants, provides cost-effectiveness and allows access to a greater selection of unique varieties, ensuring a fresh supply of greens across multiple seasons.
Site Selection and Starting Timing
Scallions thrive in locations that receive a minimum of six hours of direct sunlight each day, although they can tolerate some afternoon shade, especially in warmer climates. These shallow-rooted plants require a well-draining medium rich in organic matter. Before sowing, amend the planting area with a generous amount of compost to ensure good fertility and moisture retention, as waterlogged soil can quickly lead to rot.
For the earliest possible yield, seeds can be started indoors approximately eight to ten weeks before the average last expected frost date. Alternatively, direct sowing outdoors can begin as soon as the soil becomes workable in early spring. To maintain a steady supply, gardeners can continue to sow small batches of seeds every two to three weeks until late summer, or even in the fall for a mild-winter harvest.
Direct Sowing Methods
When planting scallion seeds directly into the garden bed, the tiny, black seeds should be sown very shallowly, ideally covered with no more than one-quarter to one-half inch of fine soil. Creating a shallow furrow or a two-inch-wide band is an effective way to distribute the seeds.
Plant the seeds densely, approximately one inch apart, or even in small clusters of four to eight seeds, as this initial crowding helps the delicate seedlings support one another as they emerge. After placing the seeds, gently cover them with soil and lightly tamp the surface to ensure good seed-to-soil contact. Initial watering should be done with a fine mist or a gentle shower to prevent the shallowly placed seeds from being displaced or washed away.
Post-Germination Care
Once the seeds germinate, typically within one to two weeks, the focus shifts to maintaining consistent environmental conditions. Scallions have a limited root system and depend on steady moisture, so the soil should be kept uniformly moist without ever becoming waterlogged. Check the top half-inch of soil regularly and water immediately if it feels dry.
Thinning promotes the development of thicker, healthier stems. When the seedlings reach a height of two to four inches, they should be thinned to stand about one to two inches apart. This action reduces competition for light, water, and nutrients, allowing the remaining plants to mature properly. Any removed seedlings are edible and can be used as a fine, chive-like garnish.
If the plants appear pale or their growth seems stunted, a light application of a nitrogen-rich liquid fertilizer can provide a boost. Options like diluted fish emulsion or compost tea are excellent for encouraging robust, leafy growth. Avoid over-fertilizing, as overly rich soil can sometimes lead to excessive foliage at the expense of a firm white base.
Harvesting for Continuous Yield
Scallions grown from seed are typically ready for harvest between 60 and 80 days after sowing, or when the stalks reach a pencil-like thickness. The most popular method for a perpetual supply is the “cut-and-come-again” technique.
To use the cut-and-come-again method, the green tops are simply snipped off about one inch above the soil line, leaving the white base and the root system intact. The plant will regenerate new green shoots from the remaining base, allowing for multiple harvests from the same plant throughout the growing season. For a complete harvest, the entire stalk can be gently pulled from the ground, ensuring the white base is intact, though this removes the plant permanently. To sustain production, make sure to leave some plants untouched to continue growing.