Green onions, also known as scallions or bunching onions, are a popular and straightforward addition to any home garden, known for their quick turnaround and mild flavor. They are members of the allium family, distinguished by long, slender green stalks and an undeveloped white base, unlike traditional onions. Because they grow rapidly and take up little space, they are suitable for both in-ground beds and small containers, providing a continuous supply of fresh flavor for various dishes.
Preparing the Planting Site
Green onions thrive best in a location that receives full sunlight, ideally six to eight hours of direct light daily, though they can tolerate partial shade, especially in warmer climates. The quality of the soil is important, as these plants require a constant supply of moisture without becoming waterlogged. The planting medium should be well-draining, loose, and rich in organic matter to support the rapid growth of the stalks.
Before planting, incorporate a layer of well-rotted compost or aged manure into the top six inches of soil to improve fertility and drainage. Green onions prefer a slightly acidic to neutral soil pH, typically between 6.0 and 7.0. While they can be planted close together, spacing them about one to two inches apart will allow each plant adequate room to develop a usable white base.
Specific Planting Depth Requirements
The appropriate depth for planting green onions depends entirely on the material you are starting with: seeds, sets, or store-bought scraps.
Planting Seeds
For seeds, which are tiny and require light to germinate, the planting depth must be very shallow. Sow the seeds only about one-quarter to one-half inch deep, covering them lightly with fine soil or potting mix.
Planting Sets
When planting sets (small, dormant bulblets), a slightly deeper placement is necessary to anchor the plant and encourage a longer white base. Plant these with the pointed end facing up, burying the entire bulblet and covering it with one to two inches of soil. This depth promotes blanching, the natural whitening of the stem that occurs when shielded from light beneath the soil surface.
Planting Transplants or Scraps
If regrowing green onions from transplants or store-bought scraps, plant the white root end just below the soil line, ensuring the entire root structure is secured. This typically means planting to a depth of about one inch. To maximize the desirable white portion, you can plant transplants deeper, burying up to two inches of the white bulb and lightly compacting the soil around the base to keep the plant upright.
Post-Planting Watering and Thinning
Immediately after planting, a thorough watering is necessary to help settle the soil around the newly placed seeds, sets, or root structures. This initial soak removes air pockets and ensures good contact between the roots and the surrounding soil. The soil should be consistently moist, but not saturated, as green onions have shallow root systems.
Water when the top half-inch of soil feels dry to the touch, aiming to keep the environment continuously damp. If you started your green onions from seed, the seedlings will likely emerge in dense clusters and require thinning once they are a few inches tall.
Thinning involves removing excess seedlings to provide adequate space for the remaining plants to develop fully. Thin the seedlings to stand about one to two inches apart, which allows for proper air circulation and resource availability. The removed seedlings are perfectly edible and can be used immediately as small, tender green onions.