Spring onions are mild, long-stemmed onions with white bulbs and juicy green leaves — also known as scallions or green onions. Botanically, spring onions can belong to the perennial species Allium fistulosum (the Japanese bunching onion), but many young specimens of the common bulb onion (Allium cepa) are also sold as spring onions. The Danish name, forårsløg, is used for the thin, slender onion plants harvested early, before the bulb has fully formed. The whole plant is edible and is used as an aromatic green in salads, stir-fries, soups, and as a fresh topping.
Advertisement: The page displays ads and contains advertising links (affiliate links). See our advertisers here.
Both the white, cylindrical root stem and the long, hollow green leaves are eaten. The old synonym “Welsh onion” doesn’t actually refer to Wales — it comes from an Old English word meaning “foreign.” In many Asian cuisines, spring onions are a staple vegetable, while in the West they are most often used as a mild flavouring and garnish.
Estimated reading time: 9 minutes
History and Origins
Onions have been cultivated for thousands of years. The earliest known descriptions of onions come from Mesopotamia, and in ancient Egypt, onions served as both food and currency. Onions spread via trade routes to Europe and Asia, where they developed into a wealth of species and varieties.
From East Asia to Danish Gardens
The green spring onions we know today originate mainly from East Asia, where Allium fistulosum was selected for its strong, pungent leaves and its ability to form clumps through side shoots. In Europe, onions were mainly selected for large, round bulbs (Allium cepa). Modern spring onions are therefore either young bulb onions or true bunching onions, which form perennial clumps.
Flavour and Aroma
Spring onions have a milder, fresher flavour than mature onions, with a sweet, slightly sharp note that becomes more pronounced in the white part. The green leaves are crisp and juicy with a more vegetal flavour, while the white base is juicier and a little sharper.
When spring onions are cooked briefly, they retain a pleasant crispness; longer cooking gives a softer texture and a sweeter, almost caramelised onion flavour. Spring onions are often used raw as a garnish or topping on hot dishes, but they can also be sautéed, grilled, or deep-fried.
Culinary Uses
Spring onions are versatile and can add crunch, colour, and aromatic onion flavour to many dishes. The green leaves and the white part can be used together or separately.
In the Danish Kitchen
In Denmark, spring onions are mainly used as a fresh flavouring: finely chopped over smørrebrød (Danish open sandwiches) and salads, stirred into potato salad or a cold dip, and as a mild oniony touch in scrambled eggs and omelettes. Their fresh, mild flavour makes them an easy alternative to ordinary onion when you want to avoid too strong a sharpness.
Popular Ways to Use Spring Onions
- Salads and cold dishes: Finely slice spring onions and sprinkle them over green salads, potato salad, or pasta salad for a fresh oniony touch.
- Wok and stir-fry: Sauté pieces of spring onion briefly with other vegetables, tofu, or meat in Asian dishes. Add the white part early and the green leaves at the end to preserve colour and crispness.
- Soups and broth: Spring onions can form a base together with garlic and ginger in miso and noodle soups. The green leaves are used as a garnish on ramen and pho.
- Pancakes and bread: In Chinese cuisine, scallion pancakes are made by rolling chopped spring onions into an oiled dough and frying them until crisp. The green leaves can also be baked into focaccia or bread.
- Grilling and baking: Whole spring onions can be grilled or baked with a little oil and salt until lightly caramelised. They make a delicious garnish for meat and fish.
- Dips and sauces: Blend spring onions with herbs, chilli, and oil into a green salsa or sauce. The white pieces can be finely chopped and used in dressings, mayonnaise, and butter.
- Eggs and omelette: Add slices of spring onion to omelettes, scrambled eggs, or egg muffins for colour and a mild onion flavour.
- Fermentation: In Korean cuisine, spring onions are used to make pa-kimchi, a spicy fermented onion dish served as a side dish.
Preparation and Cooking
Although spring onions are easy to use, proper preparation can improve both flavour and appearance.
Basic Preparation
- Cleaning: Rinse the whole plant in cold water to remove soil and sand between the leaves. Remove any wilted or slimy leaves.
- Trimming: Cut off the root end of the white part and the tips of the green leaves if they are dry. Save the roots for replanting if you want to grow new shoots.
- Cutting: Cut spring onions into thin rings or diagonal pieces, depending on the dish. The white part can also be finely chopped as a substitute for garlic or onion in dressings.
Cooking Methods
- Raw: Finely chopped spring onions add crunch and mild flavour to salads, sandwiches, sushi, and wraps.
- Sautéing: Sauté slices of spring onion in oil or butter for 2-3 minutes until soft and aromatic. Perfect in rice dishes, scrambled eggs, or as a base for sauces.
- Grilling and baking: Brush whole spring onions with oil and grill for a couple of minutes on each side until lightly charred. In the oven, they can be baked at a high temperature with oil and salt, optionally with parmesan.
- Blanching: For a milder flavour, spring onions can be blanched for 30 seconds in boiling water and then cooled in ice water.
Health Benefits
Spring onions are nutrient-rich while being low in energy. A raw stalk contains around 25 calories and consists primarily of water and dietary fibre. They are good sources of vitamins and minerals.
Vitamins, Minerals and Antioxidants
- Vitamins: Spring onions contain high amounts of vitamin A (as provitamin A in the green leaves), C, and K. A serving contributes significantly to the daily requirement for these vitamins, which support immune function, bone health, and wound healing. According to analyses of Allium fistulosum, 100 g of raw spring onion contains around 27 mg of vitamin C and 193 µg of vitamin K, far more than many other vegetables.
- Minerals: The white onion parts and green leaves are rich in potassium, calcium, iron, and magnesium. Potassium helps regulate blood pressure, while calcium and magnesium strengthen bones and muscles.
- Antioxidants: Spring onions contain flavonoids and organosulfur compounds, which may have anti-inflammatory and cholesterol-lowering properties. They are related to garlic and onions, which have well-known health benefits.
- Dietary fibre: The green leaves contribute dietary fibre, which aids digestion and provides satiety without many calories.
Good to Know
Because of their high vitamin K content, people taking blood-thinning medication should consult their doctor about the amount of spring onion in their diet. In addition, people with an onion allergy may experience discomfort, but this is relatively rare.
Growing
Spring onions are easy to grow and thrive well in Danish gardens and on balconies. They can be grown as annuals or perennials, depending on the variety (Allium fistulosum forms perennial clumps).
How to Grow Spring Onions
Total time: 8-10 weeks
- Sow the seeds
Sow seeds from early spring (March) to midsummer (July) for a continuous harvest. Sow in rows 2-3 weeks apart for a steady supply.
- Sowing depth and spacing
Sow the seeds 1 cm deep in loose, nutrient-rich soil. Keep 1-2 cm between seeds and about 15-20 cm between rows.
- Water evenly
Keep the soil evenly moist, especially during germination and dry spells. Spring onions need less water than storage onions, but must not dry out.
- Feed and weed
Work compost into the soil before sowing, and apply an organic nitrogen-rich fertiliser during the growing season. Avoid too much nitrogen, as it can make the leaves soft.
- Harvest
Harvest once the plants have reached pencil thickness and a height of 15-30 cm, typically 8-10 weeks after sowing. Gently pull up the plant or cut it down at soil level; bunching types will send up new shoots from the root.
- Regrow from the root
Keep the bottom centimetre of the white root, place it in a glass of water on the windowsill, and new green shoots will sprout within a few days. Then plant it in soil to continue growing.
Growing Conditions
- Light: Spring onions thrive in full sun but can tolerate light shade. 6-8 hours of direct sunlight gives the best flavour and vigour.
- Temperature: Optimal growth occurs at 15-25 °C. They tolerate light frost, but severe cold can stunt growth.
- Soil: A light, humus-rich, well-drained soil with a pH of 6.0-7.0 is ideal. Avoid compacted clay soil, as it can cause misshapen, coarse roots.
- Water: Water regularly so the soil never dries out completely. Mulch can help retain moisture and reduce weeds.
Storage
Harvesting at the right time and storing them correctly ensures that spring onions retain their crispness and flavour.
In the Fridge and Long Term
- Harvesting: Harvest the largest onions continuously and leave the small ones to keep growing. Pull up the plants while the soil is moist so the roots don’t break. Alternatively, the plants can be cut down to a couple of centimetres above soil level so they can resprout.
- Fridge: Store spring onions unwashed in the fridge. Remove the outer leaves, wrap them in a damp paper towel, and place them in a closed bag or container. They stay crisp for 3-5 days.
- Keep away from fruit: Store them away from apples and bananas, as these release ethylene, which causes the leaves to yellow.
- Long-term storage: The green leaves can be chopped and frozen for later use in soups and stews. They can also be pickled or fermented into kimchi.
Flavour Pairings
The mild onion flavour of spring onions makes them a perfect partner for many other ingredients:
- Herbs: Parsley, coriander, basil, and mint complement spring onions in salads and Asian dishes.
- Spices: Ginger, chilli, garlic, sesame, and soy sauce bring out the fresh onion flavour.
- Citrus: Lime or lemon juice adds acidity and freshness to dips and dressings.
- Vegetables: Spring onions go well with tomatoes, cucumbers, radishes, carrots, and cabbage in salads and stir-fries.
- Protein: The white and green parts are delicious with eggs, tofu, fish, prawns, chicken, and beef — for example in omelettes, fried rice, or fajitas.
Look-Alikes and Quality
Spring onions can be confused with other members of the onion family. They resemble grass-like chives (Allium schoenoprasum), but chives have thinner, tubular leaves and no white bulb. They can also be mistaken for young leeks (baby leeks) or thin leaf celery.
When buying spring onions, look for fresh ones with a firm, white root and crisp, dark green leaves free of yellow or slimy patches. Avoid ones with wilted leaves or dry roots.
Sustainability and Biodiversity
Spring onions are relatively resource-efficient to grow, as they grow quickly and can be harvested several times from the same plant. They belong to the onion family, whose flowers attract pollinators such as bees and hoverflies, if the plants are allowed to flower.
By growing spring onions as part of a crop rotation, you can help keep the soil healthy and break disease cycles. There are many varieties with different flavour nuances and hardiness; growing several varieties helps preserve genetic diversity.
Traditional and Modern Use
In Asia, spring onions have been an indispensable ingredient for centuries. In China, they are used both raw and fried in dishes such as congee, jiaozi filling, spring rolls, and cold noodle salads. In Japan, they are used as a topping for ramen, donburi, and okonomiyaki, and in Korea, they feature in kimchi and in small, deep-fried pa-jeon pancakes. In the Middle East and the Mediterranean, spring onions are sprinkled over mezze dishes such as tabbouleh and hummus, or used in salads with tomato and cucumber.
In the modern, global kitchen, spring onions have earned a place as a flavouring and garnish. Their colourful green strips add contrast to everything from avocado toast to ramen and pizza. The “zero waste” food trend has also increased interest in reusing spring onion roots to grow new plants on the kitchen counter: place the cut-off base in a little water, and new green shoots will sprout within a few days.
Try This Recipe
Spring onions are a classic topping for Asian egg dishes, where the fresh onion flavour and crisp green strips balance the soft egg and juicy prawns. Sprinkle them on at the end so their colour and crispness are preserved. Try our recipe for Foo Young Chinese Omelette in the Air Fryer – a fluffy omelette with prawns in 12 minutes.
Equipment and Products
In wok and teriyaki dishes, spring onions pair beautifully with a sweet-salty glaze that ties the onion’s freshness to meat, tofu, or fish. A ready-made glaze makes everyday cooking easy without compromising the Asian flavour profile. We use, among others, Kystfiskens Teriyaki Glaze for exactly this type of dish.
Frequently Asked Questions
Yes. The terms are often used interchangeably. Scallion, green onion, and spring onion all refer to the same vegetable. They can come from Allium fistulosum (bunching onions), which doesn’t form a bulb, or from young specimens of Allium cepa. The flavour and uses are the same.
Yes. Both the white base and the green leaves are edible. The white part is slightly more aromatic, while the green leaves are milder and fresh. Many recipes use both parts; others use them separately depending on cooking time.
Yes. Cut off the bottom centimetre with the roots from your shop-bought spring onions and place them in a glass with a little water on the windowsill. After a few days, new green shoots will sprout. Plant them in pots with soil if you want a longer-lasting supply.
Yellow leaves are typically caused by either a lack of nutrients, too much water or heat, or the plant reaching the end of its growing season. Ensure even watering, light fertilising, and a moderate temperature. Harvest continuously to stimulate new growth.
Chives are a different species (Allium schoenoprasum) with thin, hollow leaves and no bulb. They taste milder and grassier and are used mainly as a herb. Spring onions have a distinct white stem and thicker leaves with a stronger onion flavour.
Facts About Spring Onions
| Field | Value |
|---|---|
| English name | Spring onions |
| Latin name | Allium fistulosum (or young Allium cepa) |
| Family | Amaryllis family (Amaryllidaceae) |
| Plant type | Perennial plant (often grown as an annual) |
| Height | 20-40 cm |
| Hardiness | Tolerates light frost; grown as a cool-season crop |
| Light | Full sun to light shade |
| Soil | Light, humus-rich, well-drained soil, pH 6-7 |
| Sow/plant | Sow seeds from March to July; 1 cm deep, 1-2 cm between seeds |
| Flowering/Harvest | Harvest 8-10 weeks after germination; flowers in summer if the plants are left to grow |
| Calories per 100g | Approx. 32 kcal |
| Flavour | Mild, sweet, and slightly sharp onion flavour with crisp green leaves |
| Culinary use | Salads, stir-fries, soups, pancakes, dips, grilling, garnish |
| Storage | Fridge: 3-5 days wrapped in damp paper; can be frozen or fermented |
