If you want a fresh and flavorful green that grows almost anywhere, look no further than bunching onions. These versatile alliums are a garden favorite for good reason, offering a continuous harvest with minimal fuss.
They’re perfect for pots, raised beds, or tucked into garden corners. You can snip the green tops for a mild onion flavor or pull the whole plant. Their ease makes them ideal for beginners and seasoned growers alike.
Bunching Onions – Fresh and Flavorful Green
Unlike bulbing onions, bunching onions form dense clumps of slender, hollow greens. They are sometimes called scallions or green onions, though true bunching onions are a specific perennial type. Their taste is fresher and more subtle than a standard onion, perfect for raw or cooked dishes.
Why Grow Bunching Onions?
There are so many benefits to adding these plants to your garden. They are one of the most reliable crops you can choose.
- Continuous Harvest: You can cut leaves as needed, and they regrow quickly.
- Space Savers: They fit in tiny spaces, even between other vegetables.
- Fast Growers: You can start harvesting in just a few weeks from planting.
- Pest Resistant: They have few serious pests or diseases.
- Soil Improvers: Their roots help break up soil and can deter some pests.
Choosing the Right Variety for You
Not all bunching onions are the same. Picking the right one depends on your climate and taste.
Popular Bunching Onion Types
- ‘Evergreen Hardy White’: A classic, cold-tolerant variety that survives winter in many zones. It forms thick white stalks.
- ‘Tokyo Long White’: Produces long, straight, and tender shafts with a sweet flavor. Excellent for salads.
- ‘Red Welsh’: Beautiful with reddish-purple bases. It’s very cold-hardy and ornamental in the garden.
- ‘Shimonita’: A Japanese variety known for its exceptional sweetness and thick stems.
- ‘Deep Purple’: Offers stunning color all the way up the stalk, great for garnishes.
How to Plant Bunching Onions Successfully
Getting your onions started is straightforward. You can grow them from seed, sets, or transplants.
Starting from Seed (The Most Common Method)
Seeds give you the most variety choice and are very economical. Here’s how to do it right.
- Timing: Sow seeds directly outdoors 4-6 weeks before your last frost date. For a continual harvest, sow every 3-4 weeks.
- Soil Prep: Choose a spot with loose, well-draining soil. Work in some compost. They prefer a soil pH between 6.0 and 7.0.
- Sowing: Plant seeds about ¼ inch deep, spacing them 1 inch apart in rows 12 inches apart. You can also broadcast them in a wide row.
- Watering: Keep the seed bed consistently moist until seedlings emerge, which takes 7-14 days.
- Thinning: Once seedlings are a few inches tall, thin them to about 2 inches apart. You can eat the thinnings!
Planting Transplants or Divisions
If a friend has a clump, you can easily start your own. In spring or fall, gently dig up a clump and separate it into smaller bunches of 3-5 shoots. Replant these divisions immediately, water them well, and they’ll establish fast.
The Ideal Growing Conditions
Bunching onions are adaptable, but they do have preferences. Meeting these needs ensures the best harvest.
Sunlight and Location
They thrive in full sun, meaning at least 6-8 hours of direct light daily. They will tolerate partial shade, but growth will be slower and the stems may be thinner.
Soil and Water Needs
The soil should be fertile and drain well. Water is crucial for tender growth. Provide about 1 inch of water per week, more during hot, dry spells. A layer of mulch helps retain moisture and suppress weeds.
Feeding Your Plants
They aren’t heavy feeders, but a little nutrition boosts growth. Side-dress plants with a balanced organic fertilizer or compost tea about a month after planting. A second feeding in mid-summer keeps perennial clumps productive.
Ongoing Care and Maintenance
A little routine care is all it takes to keep your plants healthy. The main tasks are simple.
- Weeding: Keep the area around onions weed-free, especially when plants are young. Weeds compete for nutrients and water.
- Hilling (Blanching): For longer, tender white stems, gently mound soil up around the base of the plants as they grow. This blocks sunlight.
- Dividing Clumps: Every 2-3 years, perennial clumps can become overcrowded. Dig them up in early spring or fall, divide, and replant to renew vigor.
Harvesting Your Bunching Onions
This is the rewarding part! You have two main ways to harvest, depending on your needs.
Harvesting Green Tops (Cut-and-Come-Again)
For a steady supply of greens, use scissors to snip leaves about an inch above the soil. Start when plants are 6-8 inches tall. They will regrow several times through the season. This method is best for perennial types.
Harvesting Whole Plants
You can pull the entire plant whenever it reaches the size you want, usually pencil-thickness or larger. Gently loosen the soil with a fork first if needed. Harvest from the outside of the clump, leaving the inner plants to continue growing.
Storing Your Fresh Harvest
For the best flavor, use your bunching onions right away. But if you have a surplus, here’s how to keep them fresh.
- Short-Term (Refrigerator): Rinse, pat dry, wrap in a slightly damp paper towel, and place in a plastic bag in the crisper drawer. They’ll last for over a week.
- Long-Term (Freezing): Chop onions and spread them on a tray to freeze individually. Then transfer to a freezer bag. They’ll keep for months, though texture will be softer—best for cooking.
- Other Methods: You can also dry the greens or pickle the white stems.
Common Pests and Problems (And Simple Solutions)
Bunching onions are tough, but a few issues can pop up. Here’s what to watch for.
Onion Thrips
These tiny insects cause silvery streaks on leaves. A strong spray of water from the hose can dislodge them. For bad infestations, insecticidal soap is effective.
Onion Maggots
The larvae of a small fly, they tunnel into roots. Use floating row covers to prevent the fly from laying eggs. Rotating your onion bed location each year helps alot.
Downy Mildew
This fungal disease appears as fuzzy, purplish-gray patches on leaves. It’s common in wet weather. Improve air circulation, avoid overhead watering, and remove affected plants.
Using Bunching Onions in Your Kitchen
Their mild, fresh flavor enhances so many dishes. Use both the white and green parts.
- Raw: Finely slice for salads, tacos, sandwiches, and garnishes for soups or baked potatoes.
- Sautéed: A gentle cook in oil or butter makes a sweet, aromatic base for stir-fries, omelets, and fried rice.
- Grilled: Toss whole onions with oil and grill until slightly charred for a fantastic side dish.
- In Stocks & Sauces: Adds a subtle depth of flavor without overpowering.
Companion Planting Benefits
Planting them near certain crops can help your whole garden. Their strong scent can mask other plants from pests.
- Great Companions: Carrots, beets, lettuce, cabbage family plants, tomatoes, and roses.
- Avoid Planting Near: Peas and beans, as onions may inhibit their growth.
Growing Bunching Onions in Containers
No garden? No problem. They excel in pots. Choose a container at least 8 inches deep with drainage holes. Use a quality potting mix. You can plant seeds or transplants more closely than in the ground—just harvest a bit earlier. Keep container plants well-watered, as pots dry out faster.
FAQ About Bunching Onions
What’s the difference between bunching onions and green onions?
Often used interchangeably, but true bunching onions are a perennial type that forms clumps. “Green onion” is a more general term for any onion harvested young with its green top.
Can you regrow store-bought bunching onions?
Yes! Place the white root ends (with about an inch of stalk) in a glass of water on a windowsill. Change the water every few days. New green growth will appear quickly. You can then plant them in soil for a longer-term plant.
How long does it take to grow bunching onions from seed?
You can begin harvesting thinnings in about 30 days. For full-sized plants, expect to wait 60-80 days depending on the variety and growing conditions.
Do bunching onions come back every year?
Many varieties are perennial in zones 5 and warmer. In colder climates, they may die back in winter but often return in spring if mulched. Treating them as an annual with successive plantings is also common.
Why are my bunching onions so thin?
Thin onions are usually caused by overcrowding, insufficient sunlight, or lack of nutrients. Thin plants to proper spacing, ensure they get full sun, and consider a light fertilizer application.
Can I eat the flower of bunching onions?
Absolutely. The round, white flower heads are edible and have a strong onion flavor. They make a unique garnish. However, allowing the plant to flower can signal it to put energy into seed production, which may slow leaf growth.
Adding bunching onions to your garden plan is a simple decision with delicious rewards. With minimal effort, you’ll have a constant supply of a fresh and flavorful green right outside your door. They’re a foundational crop that proves great gardening doesn’t have to be complicated. Give them a try this season—you might find they become one of your most valued plants.