Stephen Albert
Scallions are green onions. They are immature onions that have not formed a white bulb.
Scallions are sometimes called spring onions. Scallions are not a specific onion variety but they are often grown from a type of onion called bunching onions. Bunching onions are a type of perennial onion that never form bulbs. That said (and not to be confusing), scallions can be grown from all kinds of onion varieties. They can be thinnings of young globe onions or young Welsh onions.
If you plant seeds or sets of regular onions, then harvest them while they are young and have not yet formed a bulb, you have a scallion. If you harvest bunching onions, you have scallions.
Scallions are mild flavored. The base and leaves are used raw in salads, as a garnish, or in cooking.
Here is your complete guide to growing scallions!
About Scallions
- Scallions are onions. To grow scallions, you can choose an onion variety specially adapted for use as green onions, choose varieties described as scallions or bunching onions. These green or bunching onions are grown for their green tops, not bulbs. These varieties will have a milder flavor than regular onions. Many scallion varieties will be ready for harvest in about 60 days from seed sowing.
- To grows scallions from regular bulbing onions (1) plant seeds; (2) plant baby plants; (3) plant sets; sets are bulbs about the diameter of a dime that were grown last year and harvested at a small size specifically for the purpose of planting as sets the following year. If you harvest these bulbing onions while young before bulbs form and use them for their green tops–these are also called scallions.
- Scallion botanical names: Allium cepa (globe onion, green onion, scallion); Allium fistulosum (bunching onion, scallion); Allium spp.
- Allium fistulosum plants are commonly grown as scallions. They form hollow cylindrical stalks that are similar in appearance to chives, and they are used in the same way. These plants do not form bulbs; they have a slight bulge at the bottom of a white stalk or shank.
- Scallion varieties are grown as annuals; they are harvested about 50 to 70 days after they are planted. If not harvested, scallions spread or “bunch” in clumps; the roots form new plants if not removed from the ground.
- Scallions are easily grown in USDA Zones 4 to 9. (Scallions are native to temperate regions of China.)
- Scallions are also known as Welsch onions (though they are not native to Wales), green onions, bunching onions, and Japanese bunching onions. Scallions are sometimes called “spring onions” but true spring onions are the species Allium cepa. A. cepa will form bulbs if left in the ground; they are called spring onions because they are commonly harvested in spring before they form bulbs.
- Scallions should not be confused with scallions which are a different plant. Scallions are also not baby or small leeks.
- Yield. Clumping types: plant one clump per person. Non-clumping types: grow 20 plants or more per person.
When to Plant Scallions Outdoors
- Scallions are commonly started directly in the garden from seed.
- Sow scallion seeds outdoors as soon as the soil is workable in early spring. Scallions started in early spring can be harvested in late spring or early summer.
- You can also direct sow scallion seeds in late summer or early fall for an autumn harvest.
- In a cold-winter region plant scallions in late fall and winter them over; you will have scallions in early spring.
- In mild winter regions, scallions can be grown through the winter.
When to Start Scallion Indoors
- Sow seeds indoors four weeks or more before the average last frost date in spring.
- Start seeds in seed trays or small pots using a sterile seed starting mix or potting soil.
- Set trays or pots in a sunny windowsill or under grow lights. Turn seedlings every couple of days so that they grow straight.
- You can begin harvesting indoors or transplant seedling to the garden after the last average frost date.
Where to Plant Scallions Outdoors
- Plant scallions in full sun.
- Plant scallions in humus-rich, well-drained soil. Add aged compost to the planting bed before planting. You can also add a granular balanced organic fertilizer to the planting bed ahead of planting.
- Loosen the soil several inches deep and enrich each planting hole with compost or work compost into the top several inches of soil.
- In rainy regions or where the soil is slow to drain, plant scallions on mounded or raised beds. Beds rich in organic matter will drain quickly.
Planting and Spacing Seeds
- Space scallions 1/2 to 1 inch apart in wide rows. In single rows, space scallions 2 inches apart and space rows 9 to 12 inches apart.
- Cover seeds or sets with 1/2 to 1 inch of finely work soil, vermiculite, or sand. Firm the soil to be sure the seeds make contact with the soil. Then lightly moisten the soil.
- Plant sets just below the soil line and then apply a light mulch.
- Seeds can be planted thickly and thinned by harvesting.
- You can also plant onion sets rather than seeds.
- Seeds can be planted thickly and plants can be thinned by harvesting.
- It takes about 60 days from seed to harvest scallions.
Planting and Spacing Scallion Sets
- In spring and summer, plant sets just below soil level and then apply a light compost mulch.
- In fall plant sets 2 to 4 inches (5-10cm) deep and cover with several inches of mulch.
- Planting sets will bring a harvest of scallions in a few weeks.
Container Growing Scallions
- Grow scallions in a pot that is at least 12 inches (30cm) across and 8 inches (20cm) deep.
- Use compost-rich potting soil.
- Scatter seeds and then gradually thin young scallion plants to about 2 inches apart. Allow enough room between plants for good air circulation.
Succession Planting Scallions
- Sow scallion seeds every 2 to 3 weeks to ensure continued harvest through the growing season.
Planting Scallions for Autumn and Winter Harvest
- Sow scallion seeds in late summer or fall so that the seedlings become established before the dormant period. Protect plants through the winter with mulch or grow them under the protection of a plastic tunnel.
Watering Scallions
- Water scallions often but lightly at the soil level Avoid wetting the foliage which can lead to disease.
Feeding Scallions
- Feed scallions with liquid fertilizer–kelp, fish emulsion–or a balanced organic fertilizer every three to four weeks
Caring for Scallions
- Mulch around scallion with aged compost or grass clippings to conserve moisture and add nitrogen to the soil.
- Mulch scallions with straw in autumn to protect them from cold; this is especially important in Zone 5 and colder.
- Scallions have a shallow root system and can not compete with weeds for moisture and nutrients. Remove weeds growing near scallions by hand pulling or cultivating gently to avoid damaging roots. Check for weeds and remove them every couple of weeks.
- Where the ground freezes in winter, pot up scallion divisions and bring them indoors to a cool, bright spot to overwinter.
Scallions Pests
- Scallions can be attacked by many of the pests that attack onions. Use organic pest controls.
- Onion maggots (Delia antique) are small white larvae that bore narrow tunnels into roots. The maggots are the larvae of small gray flies. Remove and destroy infected plants.
- Leaf miners are black fly larvae that tunnel into leaves; exclude flies from laying eggs on young plants with floating row covers.
- Nematodes are slender, translucent worms that live in the soil and feed on roots; they can leave plants distorted and twisted. Crop rotation is the best way to control nematodes.
- Thrips are sucking insects that attack scallion shoots. Control thrips with neem oil, and insecticidal soap, or spray them off plants with a garden hose.
Scallion Diseases
Scallions are susceptible to diseases that attack onion plants.
- Damping off is a fungal disease that causes young green shoots to wilt and die shortly after they emerge from the soil. Make sure there is good air circulation in the planting bed and do not overwater.
- Downy mildew is a fungal disease. Leaves develop yellow spots with fluffy fungs spots on the undersides. Destroy infected plants; drench the soil with compost tea; avoid wetting foliage.
- Leaf blight is a fungal disease. Leaves develop brown spots. Remove infected plants; space plants widely to increase air circulation.
- Onion smut is a fungal disease that attacks young seedlings. It causes blister-like lesions near the base of the plant and leaves become streaked. Some fungicides may be effective. Make sure there is good air circulation. Rotate crops each season.
- Pink root got is a fungal disease that caused roots to turn light pink then plants shrivel and become stunted. Plant early in the season to avoid this disease. Plant disease-resistant varieties.
- Rust is a fungal disease that causes rust-colored spots on leaves and stalks. Plant early in the season to avoid this disease and rotate crops.
Harvesting Scallions
- Harvest scallions when they are about as thick as a pencil and at least 6 inches tall.
- Use a trowel to uproot the plants. Avoid pulling on the plants; the stems break easily.
- With clumping varieties, harvest as many stems as you need, then replant the cluster.
- To increase the number of shoots or to start a new clump, separate single shoots and replant them.
- Replant clumps or single shoots in a new spot; this is a form or crop rotation to avoid diseases.
- To harvest scallions as the ideal size, succession plants them.
- Keep harvesting them as needed for fresh eating.
- Uproot the plant with a trowel; if you pull them, the stem break easily
- Harvesting scallions improve the growing conditions for the remaining plants by loosening the soil and removing competition.
Storing Scallions
- Scallions will keep for about one week in the refrigerator, not longer.
- Stand the root end of scallions in a jar of water and place a plastic bag over the long green tops to keep them fresh.
- If the water gets murky, replace it with fresh water.
Scallions in the Kitchen
- Scallions are mild flavored. The base and leaves of scallions can be used raw in salads, as a garnish, or in cooking.
- Use scallions to add a mild onion flavor to savory dishes.
Scallion Frequently Asked Questions
Q: What are scallions?
A: Several kinds of onions with long straight bulbs are used for scallions. You can harvest all varieties of onions immature before they form bulbs and call them scallions. You can also grow perennial bunching onions and call them scallions. Bunching onions form many small, narrow bulbs, or stalks, rather than one fat one.
Q: What’s the difference between scallions, green onions, and spring onions?
A: There is no difference. They are all the same.
Q: Why are bunching onions commonly grown as scallions?
A: Bunching onions form many narrow, bulbs or stalks, unlike globe onions which form one fat bulb. Bunching onions are a type of perennial onion. Once they are sown they will continue to divide on their own. They die back in winter and reappear in spring. When you grow scallions from bunching onions, leave some behind at harvest time; they will continue to grow and divide.
Q: What part of a scallion is edible?
A: All parts of the scallion are edible–the green straight leaves, the long white stem or shank, and the root below.
Q: Will scallions survive through the winter?
A: Yes. Scallions grown from bunching onions are perennials and will die back in winter and reappear in spring.
Q: Can I grow scallions in winter?
A: Yes. In mild winter regions, scallions can be grown in planting beds throughout the winter. In cold-winter regions, grow scallions under the protection of a plastic tunnel or cold frame.
Scallion Varieties to Grow
- ‘Asagi Bunching’: high yield; mild flavor; 65 days to harvest.
- ‘Beltsville Bunching’: slight bulbs; hardy in winter; 65 days to harvest.
- ‘Deep Purple’: bunching type; red-colored shanks; 60 days to harvest from seed.
- ‘Emerald Isle’: strong straight tops; long white bulbless shank; heat tolerant; 64 days.
- ‘Evergreen Long White’: bunching type; hardy; plant in spring or fall; 60 days to harvest from seed.
- ‘Ishikura Improved’: bunching type; grows to 30 inches (75cm) tall; sow in a trench and then hill stems to keep them white; 50 days from seed.
- ‘Long White Bunching’: white shafts with bulbs; tolerant of fusarium and pink root; 70 days.
- ‘Red Baron’: bunching type; red stems, green leaves; 65 days from seed.
- ‘Red Welch Bunching: red, bulbless onions; 65 days.
- ‘Southport White Globe’: mild flavor; 65 days.
- ‘Tokyo Long White’: non-bunching; long stalks; 65 to 95 days from seed.
- ‘White Bunching’: 18-inch-long, white stalks; endures heat; 40 days.
- ‘White Lisbon’: resistant to heat and cold; 65 days.
- ‘White Spear Bunching’: long, slender white stalks; 60 days.
- ‘White Sweet Spanish Bunching’ slow to form bulb; mild flavor; 65 days.
- ‘Winter White Bunching’: excellent overwintering type; 60 days.
- ‘Yakko Summer’: withstands summer heat; 100 days.
- ‘Zippy’: hybrid, resistant to pink root; 65 days.
