Scallions (Allium fistulosum) bring the flavor of onions without the long wait in the garden or the peeling in the kitchen. Although the terms scallions, green onions, and spring onions are often used interchangeably to mean any onion harvested before the bulb fully forms, they are actually distinguished from one another as follows:
- Green onions: These are regular onions (Allium cepa) harvested when they have very small bulbs; the leaves are good for eating.
- Spring onions: These are Allium cepa onions harvested when the bulb is smaller than a quarter; the leaves are edible but not good for eating.
- Scallions: These are clump-forming onions with very thin bulbs; the leaves and bulbs are good for eating and are often more tender and mild than those of green onions.
Scallions are perennials that form long, dark green, tubular leaves that change to white bulbs underground, despite being considered "bulbless" onions. The leaves can reach up to 3 feet in height but are typically harvested when they're around a foot tall. Both the stalk and the bulb are prized for their bright yet mild onion flavor, and they are usually eaten raw. Scallions have a rapid growth rate and are ready to harvest in 60 to 80 days after sowing. They are typically planted in the spring. If you have pets, it's important to note that scallions can be toxic to them.
|Common Name||Scallion, green onion, spring onion, bunching onion|
|Botanical Name||Allium fistulosum|
|Plant Type||Perennial, bulb|
|Size||1–3 feet tall, 1–2 feet wide|
|Sun Exposure||Full sun|
|Soil Type||Sandy, loamy, well-drained|
|Soil pH||Acidic to neutral (6.0 to 7.0)|
|Hardiness Zones||6–9 (USDA)|
|Toxicity||Toxic to pets|
Watch Now: How to Grow Scallions
How to Plant Scallions
When to Plant
Scallions are best planted in the spring for a summer harvest. In climates where scallions grow well as perennials, they can be harvested year-round without replanting.
Selecting a Planting Site
Choose a sunny spot in the garden with well-draining soil for scallions. They also grow well in containers. Be sure to keep weeds away from scallions to avoid competition for soil moisture and nutrients. A layer of mulch can help keep weeds down.
Spacing, Depth, and Support
Plant seeds about 1/4 inch deep, and plant seedlings at the same depth they were growing in their previous container. Space plants roughly 2 to 3 feet apart in rows that are 1 to 2 feet apart. A support structure typically isn’t necessary.
These are leafy vegetables that can handle a bit of shade. But they do best and remain healthiest in full sun, meaning at least six hours of direct sunlight on most days.
Scallions prefer a rich, sandy loam that has sharp drainage and a slightly acidic to neutral soil pH. Add organic matter, such as compost, to the soil around 6 to 8 inches deep when planting to boost growth.
Scallions have a shallow root system, so regular watering and/or rainfall is a must as soon as the soil starts to dry out. However, do not let the plants sit in wet soil, which can lead to rot and other diseases. The soil should be consistently moist but not soggy. A drip irrigation system will keep roots well-watered while protecting foliage from excess moisture, which also can cause disease.
Temperature and Humidity
Scallion seeds generally need a soil temperature of at least 45 degrees to germinate, though warmer is better. The plants like temperatures between 68 and 78 degrees. They do not mind humid conditions, as long as they have good drainage to prevent rot and other diseases.
Give your plants a balanced fertilizer, following label instructions. Fertilizer that is high in nitrogen, such as fish emulsion, will keep them green and growing.
Scallions self-pollinate, though it's best not to let them flower as this can impact the taste of the leaves.
Types of Scallions
There are several scallion varieties, including:
- 'Guardsman': This variety is ready for harvesting within 60 days of planting.
- 'Nabechan': This is a Japanese variety prized for its flavor.
- 'Red Beard': This one features purple-red stalks and is quick and easy to grow.
- 'Tokyo Long White': This is another flavorful perennial variety with long, slender stalks.
Scallions vs. Garlic
The leaves of a garlic plant can sometimes be mistaken for scallions. They’re both tall, narrow, and green. However, a telltale difference is the garlic leaves will smell faintly like garlic while the scallion leaves will smell like onion. The garlic leaves are also typically thicker than scallion leaves.
Scallions are tender and mild when they are young. You can start harvesting as soon as the plants reach about 6 to 8 inches tall and are as wide as a pencil, simply cutting off the leaves you need for cooking. Harvest the whole plant by pulling it out of the soil, wash it, and use as desired fresh or cooked in dishes. The fresh leaves will keep in the refrigerator for about a week. If you are growing scallions as a perennial, it is recommended that you avoid harvesting during the first season. This allows the plant to become established and produce a more bountiful crop. Then, trim off the leaves as needed.
How to Grow Scallions in Pots
Scallions grow well in containers, as their root system is fairly small. Make sure the container has drainage holes. Any container material will do, though an unglazed clay that allows excess soil moisture to escape through its walls can help to prevent root rot from overwatering. Be sure to empty the container saucer right away if it fills with water.
Scallions are often propagated by division when they are grown as perennials. Spring is the best time to divide a mature plant. Here’s how:
- Simply dig up a clump, leaving the roots as intact as possible.
- Gently pull apart the roots to create two or more sections, depending on how large the plant is.
- Replant each section in a suitable growing site, patting the soil around it and watering well.
How to Grow Scallions From Seed
You can start seeds indoors about eight to 10 weeks before your projected last frost date, or direct sow in the garden once the threat of frost has passed. Sow the seeds about 1/4 inch deep. As with other onions, germination can be slow and poor. The most important element scallion seeds need is constant moisture, which makes starting them indoors where you can keep an eye on them a good choice. Seedlings should emerge in one to two weeks. Once you have growth, thin the seedlings to about 2 inches apart. For a continual harvest, succession-plant new crops every three to four weeks.
Potting and Repotting Scallions
Use a quality, well-draining, organic potting mix when planting scallions in a container, and water at the time of planting to evenly moisten the soil. If you use a large enough container and regularly harvest your scallions to prevent them from becoming overgrown, you likely won't have to repot your plant.
If you are growing scallions as perennials, apply a thick layer of mulch in the late fall for cold-weather protection. Remove it in the spring when the soil has warmed. You will get an earlier crop this way.
Common Pests and Plant Diseases
There are several pests that can cause issues for scallions. Watch out for cutworms, onion maggots, onion nematodes, slugs, thrips, and allium leaf miner. If you start noticing problems, such as damaged foliage or lack of healthy growth, planting your next crop in a different area of the garden can help. Moreover, mildew, leaf spots, and rust can occur, especially in improper growing conditions. Make sure the plants are getting adequate sunlight and moisture.
Are scallions easy to grow?
As long as they get enough light and moisture, scallions are quite easy to grow.
How long does it take to grow scallions?
Most scallion varieties can be harvested in roughly 60 to 80 days after planting.
Can you grow scallions indoors?
Scallions usually grow well indoors by a bright window or under grow lights.