Scallions, often referred to as green onions or spring onions, are a popular and rewarding addition to any garden. These members of the Allium family are prized for their mild, sharp flavor and versatility in the kitchen. They are exceptionally easy to cultivate, thriving in small spaces and providing a garnish and flavor component for countless dishes. Scallions also have a rapid growth rate, allowing for a quick turnaround from planting to harvest.
Planting Windows and Timing
The best time to plant scallions primarily depends on your local climate, but their natural cold tolerance allows for a wide planting window. Scallions are a hardy cool-season crop, meaning they can withstand frost and low temperatures better than many other garden vegetables. Many bunching varieties are cold hardy enough to survive temperatures well below freezing, provided they are established and protected by snow or mulch.
The earliest planting opportunity comes in spring, as soon as the soil is workable. This typically means direct sowing seeds or planting starts four to six weeks before the last expected frost date. Starting seeds indoors eight to ten weeks before that date allows for a jump start, providing transplants ready once the soil temperature consistently reaches 50 degrees Fahrenheit. For an immediate harvest, gardeners can direct-sow seeds outdoors from early spring through May.
Planting in the fall is highly effective for a late-season harvest or an early crop the following spring. Sow seeds in late summer, generally August or September, allowing plants enough time to establish a root system before the deep freeze arrives. In temperate areas with mild winters, fall plantings can often be harvested intermittently throughout the cooler months. Mild climates may even support continuous, year-round scallion production.
Starting Scallions: Seeds, Sets, and Regrowth
Gardeners have three primary methods for establishing a scallion patch, each offering a different balance of speed and longevity. Starting from seed is the most common approach and offers the widest variety selection. Sow seeds about one-quarter to one-half inch deep in rows, or broadcast them in a two-inch-wide band. After seedlings emerge, thin them so plants are spaced about an inch apart, or leave them in small clumps of four to eight seedlings for mutual support.
Another method is to plant sets, which are small, immature onion bulbs harvested from the previous season. While sets are typically used for producing large bulbing onions, planting them closely together and harvesting early results in a fast crop of scallions. This method provides quicker establishment and a more robust initial plant than starting from seeds. Sets are useful for gardeners looking for a rapid yield, bypassing the long germination and vulnerable seedling stage.
A popular, immediate-yield technique involves regrowing scallions from the white, root-end sections of store-bought produce. Place the root ends in a shallow glass of water, ensuring the water covers the roots but not the cut tops. The plant will quickly produce new green shoots, often within a few days. For long-term health and continued harvest, these rooted cuttings should be transplanted into soil, as they lack the nutrients to thrive indefinitely in water.
Extending the Harvest Season
To ensure a continuous supply of fresh scallions throughout the growing season, succession planting is highly recommended. This involves sowing a small batch of seeds every two to four weeks, rather than planting the entire supply at once. Staggering the plantings prevents a glut of mature scallions and maintains a rolling harvest schedule until the first heavy frost.
The method of harvesting plays a significant role in extending the life of the crop. Instead of pulling the entire plant, use the “cut-and-come-again” technique, snipping the green stalks about an inch or two above the soil line. Leaving the white root base intact allows the plant to regenerate new leaves, often providing three to five harvests from a single bulb. If you prefer to pull the whole plant, harvest the largest ones first to give smaller neighboring plants more space and resources to mature.
Scallions can be maintained through the winter to provide an early spring crop. In colder regions, a final late-summer planting of a winter-hardy variety can be protected with a heavy layer of mulch or a cold frame after the ground freezes. This insulation shields the roots from severe temperatures, allowing the plant to survive and resume growth once the soil begins to warm. Certain perennial varieties, like bunching onions, naturally overwinter and divide, providing a renewable source of greens.