Green onions, also known as scallions or bunching onions, are members of the Allium family valued for their mild flavor and long, edible green stalks that do not form large bulbs. Proper spacing is fundamental to their cultivation, directly influencing the final yield, stem thickness, and overall plant health. Adequate room prevents competition for essential resources like water and soil nutrients, which is important for this shallow-rooted crop. Sufficient distance also ensures good air circulation, helping prevent the development and spread of fungal diseases.
Spacing When Planting Sets or Starts
Planting green onions from sets or purchased starts is a reliable method that offers precise control over the final plant arrangement. For slender, non-bulbing green onions, a close spacing of one to two inches between each plant is recommended for optimal growth. This spacing determines the density of the final harvest.
This tight spacing encourages the development of thinner, uniform stems, which are often preferred for culinary use. Increasing the spacing to three or four inches will result in thicker, more robust, and slightly more bulbous stems. The rows themselves should be spaced 12 to 18 inches apart, providing enough room for maintenance activities like weeding and ensuring light reaches all the foliage. This method allows for immediate production of a uniform crop.
Spacing When Sowing Seeds Directly
Sowing green onions directly from seed requires a different approach than using sets because seeds are typically sown more densely to account for germination rates. Seeds should be sown in a shallow trench or drill, about one-quarter to one-half inch deep, in rows spaced 12 to 18 inches apart. The initial seeding should be done thickly to ensure a full stand of seedlings.
The initial dense planting necessitates thinning once the seedlings have reached a height of a few inches. Thinning involves selectively removing excess seedlings to establish the final desired spacing. This process prevents overcrowding and should aim for a final spacing of one to two inches between the remaining young plants.
Managing Density and Crowding
Overcrowding occurs when plants are spaced too closely, leading to intense competition for light, water, and nutrients, which ultimately stunts the growth of the entire patch. When green onions are planted too densely, poor air circulation creates a damp microclimate around the base of the plants. This humid environment increases the risk of fungal diseases, such as downy mildew, which can compromise the health of the crop.
The most effective method for managing density after growth has begun is selective harvesting. As the onions mature, gardeners can pull the largest plants from the densest clusters first. This action immediately creates space for the remaining, smaller plants to continue their growth cycle. By continuously harvesting the mature onions from tight groupings, you maintain optimal spacing and ensure a sustained, healthy yield over a longer period.