Green onions, often called scallions or bunching onions, are a garden favorite because they are easy to grow and provide a continuous harvest of mild, flavorful foliage. Successfully growing these non-bulbing alliums begins with planting a small cluster of seeds together to establish a robust stand. This method leverages the plant’s natural tendency to grow in tight groupings, ensuring a plentiful supply of fresh green onions directly from your garden bed.
Recommended Seed Density
The recommended number of green onion seeds to plant in a single spot is between three and five seeds. This “clump” or “bunch” planting method is intentionally dense because onion and scallion seeds often have a lower and slower germination rate. Planting multiple seeds ensures that at least two or three seedlings will emerge in the desired location.
The resulting cluster of seedlings provides mutual support, helping the delicate sprouts stand upright against wind and light rain. Professional growers may use six to eight seeds per cell to guarantee a strong bunch. For home gardeners direct-sowing into the soil, aiming for four seeds per hole provides a good balance between ensuring success and minimizing heavy thinning later.
Sowing Techniques and Spacing
The hole for the seed clump should be shallowly prepared, as green onion seeds do not require deep burial to sprout. The optimal planting depth is only about one-quarter to one-half inch beneath the soil surface. Planting too deeply can significantly delay germination or prevent the fragile seedlings from reaching the light entirely.
When planting in distinct clumps, space these clusters about four to six inches apart to allow sufficient room for the individual plants to mature without competing for nutrients. This spacing creates manageable bunches that are easy to harvest and maintain throughout the season. Alternatively, you can opt for continuous row sowing by scattering seeds thickly in a two-to-three-inch wide band, a method that is less precise but effective for a large, dense crop. The soil must be consistently moist during the one-to-two-week germination period, as allium seeds are sensitive to drying out.
Thinning for Success
Since multiple seeds were planted, thinning is necessary to ensure the remaining plants have adequate resources. This process should begin once the seedlings are established, typically when they reach a height of two to four inches and their true leaves have appeared. Thinning prevents overcrowding, which can lead to weak stalks and increased susceptibility to disease due to poor air circulation.
When thinning a clump, select the strongest one or two seedlings to remain in that location. You can gently pull the excess seedlings out, taking care not to disturb the roots of the plants you intend to keep. A less disruptive method is to simply snip the unwanted seedlings at the soil line with small scissors, eliminating the risk of accidentally uprooting the keepers. The small plants removed during this phase are edible and can be immediately used in the kitchen, providing your first harvest of micro-scallions.