Bunching Onions 101: Beginner’s Guide to Growing Like a Pro

If you possess knowledge in gardening and cultivating edible plants, you may be intrigued by the idea of growing bunching onions. But what exactly is a bunching onion and how does it differ from a regular onion?

Bunching onions are perennial plants that develop edible green stalks and small white bulbs. The hardy plant needs rich soil, regular watering, and a thick layer of mulch to keep the soil moist. They grow well in zones 3 to 9 under full sun exposure.

Unlike regular onions, bunching onions are grown for their stalks rather than their bulbs. You can eat the succulent stalks fresh or add them to your cooking for the added flavors.

Read more to learn how to grow bunching onions in your garden.

How To Grow Bunching Onions

The more you grow vegetables in your garden, the easier it gets. And growing bunching onions is no different from other plants. In fact, it’s actually quite easy since these hardy plants need minimum care and work to keep them growing year after year.

Bunching Onion Facts

Bunching OnionFacts
Botanical NameAllium fistulosum
Other NamesWelsh onion, long green onion, Japanese bunching onion, and spring onion
Popular VarietiesEvergreen, Heshiko, Tokyo Long White, 
When To PlantEarly spring and late summer
Soil PreferencesNutrient-rich, well-drained soil
Light RequirementsFull sun
Water NeedsRegular watering
FertilizationBalanced fertilizer once every 3 weeks.
Pests/DiseasesAllium leaf miners, thrips, white rot, downy mildew, Botrytis leaf blight
Mature Size1-3 feet tall
Days Till Harvest60 days

Planting Bunching Onions

As resilient plants with hardiness for zones 3 to 9, you won’t have much trouble getting bunching onions to grow in your garden. It doesn’t require much in terms of soil type, or watering needs.

However, if you want to harvest delicious stalks, then you need to pay attention to the following growing conditions.

When To Start Bunching Onions Indoors

If you have a short growing season in your region, then you can give the bunching onions a head start by germinating the seeds indoors. The best time for indoor germination is 4 to 6 weeks before the last frost.

Keep the soil moist until the seeds germinate. The ideal temperature in the room should be between 59 and 68 degrees Fahrenheit. 

When To Plant Bunching Onions

Since bunching onions only takes about 60 days to reach maturity and be ready for harvesting the stalks, you can start them in the early spring. By mid-summer, you’ll have ripe stalks. You can also plant them in July or August to harvest the stalks in the fall.

Bunching Onion Ideal Soil

Although bunching onions are not quite particular about the type of soil you plant them in, you should provide loamy and well-drained soil. Sandy soil dries out too fast for the bulbs to absorb the moisture and nutrients while clay soil is prone to waterlogging.

Bunching Onion Spacing

Since bunching onions don’t have large bulbs, they don’t take up much space in the vegetable bed. On average, you should space the plants between 4 to 6 inches apart. That’s enough to keep them well-ventilated without wasting precious garden space.

Bunching Onions Care

When it comes to caring for bunching onions, you need to water them regularly, provide enough sunlight during the growing season, and make sure they’re fed with the right fertilizer.

The onions need at least 6 hours of full sun every day. To keep the soil from drying out too fast, you can use mulch. As for fertilizing, you can use mild comfrey tea or fish emulsion once every 3 weeks.

When To Harvest Bunching Onions

Once the stalks of the bunching onions have reached 4 to 6 inches, you can start harvesting them. Cutting off the stalks doesn’t kill the plant. They will grow back just as fast. If you want to thin your patch, pull the onions out by the roots.

How To Grow Bunching Onions in Containers

  1. Choose a pot 7 to 9 inches in diameter.
  2. Fill it with a mixture of soil and organic compost.
  3. Sow the seeds a half-inch deep and cover them with a thin layer of soil.
  4. Water lightly to keep the soil moist until the seeds germinate after 8 to 10 days.
  5. When the saplings are 2 to 3 inches long, thin them out keeping them 4 inches apart.
  6. Keep watering the plants and feed them with a mild liquid fertilizer.

Bunching Onion Companion Plants

Chamomile, summer savory, carrots, leeks, beets, strawberries, cabbage, and lettuce are among the best companion plants for bunching onions.

What Do You Use Bunching Onions For?

You can eat your bunching onions fresh or chop them into a green salad. They do well in stir-fried recipes and pasta sauce. Add them to your meat and chicken marinade for an extra spicy flavor. You can also cook them with other vegetables such as spinach.

Do Bunching Onions Multiply?

Bunching onions grow by dividing the original bulblet you planted into multiple bulblets. As long as the bulblet remains in the soil, it will keep growing and dividing. The stalks grow back after you harvest them.

Related Questions:

Are Bunching Onions Perennial?

Bunching onions are perennial plants that keep growing stalks year after year. Keep the bulblets in the soil to harvest succulent stalks during the growing season.

Why Are My Bunching Onions So Thin?

If your bunching onions look thin and the stalks are not as delicious as you expected, this might have to do with a lack of spacing. The onions should be between 4 to 6 inches apart to avoid overcrowding and competing over resources. Thin out the plants and feed them with mild fish emulsion.


Bunching onions are non-bulb perennial vegetables hardy to zones 3 to 9. Plant them in the early spring for summer harvesting or in the late summer for fall harvesting. Choose a sunny spot and rich soil to enjoy the succulent stalks throughout the growing season.