Welsh Onion
Welsh bunching onion
Allium fistulosum
Last edited on 26 Oct 2026. View history
Welsh Onion
Also known as
Japanese bunching onion (en)
green onion (en)
spring onion (en)
scallion (en)
escallion (en)
salad onion (en)
A variety of onion
How to sow Welsh onion: Division or direct seed
Sun requirement for Welsh onion: Plant in Full Sun
The Welsh Onion, or Bunching Onion, is a perennial species of onion native to China that is now grown around the world. Welsh Onions are very similar in taste and appearance to the common onion, Allium cepa. Large Welsh Onions resemble leeks and small ones look like chives. The main difference is that the stems of the Welsh Onion are hollow and their bulbs are barely thicker than their stems, which is why they are sometimes described as being "bulb-less." Plants form perennial clumps, which can be divided to propagate more onions. Welsh Onions can be grown as an annual in cooler regions where the plants cannot overwinter.
- 6
- plantings
- 20
- harvests
- 2
- seed packets
Welsh onion facts
Lifespan
Perennial
living more than two years
First harvest expected
16 weeks after plantingHeight × spread
90cm × 30cmRow Spacing
10cm median of members' seed packetsWhen to sow
Southern hemisphere
Sep–Oct
Northern hemisphere
Mar–Apr
median of members' seed packets
Grown for
stem harvested 16 timesWhat are growing degree days?
A plant grows with warmth, not with days. A growing degree day is one day's worth of useful warmth: how many degrees the day's average temperature is above the lowest temperature the crop grows at. Add them up from planting and you know how far along the crop is, whatever the calendar says.
Say that lowest temperature is 10°C. A day averaging 17°C gives 7 growing degree days. A day averaging 8°C gives none, as it is too cold for the crop to grow. That is why the same lettuce takes about 50 days in a summer and 90 in an autumn: it needs the same total warmth either way.
For Welsh onion, the FAO EcoCrop database gives a lowest growing temperature of 6°C and a shortest growing cycle of 60 days at its best temperature, about 750 growing degree days to a first harvest.
Where you've told us where your garden is, we use this and the weather there to predict when your Welsh onion will be ready to harvest. We don't use it for how long a plant lives or when it finishes: we go by what members have logged for that.
Growing Welsh onions
- Sow seeds in trays 8 weeks before planting out
- Dig compost into the bed 1 week before planting out
- Water regularly at planting out every week
- Weed around the plants 2 weeks after planting out every 2 weeks
- Feed with a nitrogen fertiliser 4 weeks after planting out every month
- Stop watering as the tops fall over 1 week before first harvest
- Lift the bulbs at first harvest
- Dry the bulbs in an airy place 1 week after first harvest
How members grow Welsh onions
Sunniness
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Planted from
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Harvested for
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Varieties of Welsh onion
Photos
PhotosWelsh onion crops
Welsh onion plantings
Welsh onion harvests
Welsh onion seeds
Video
Where Welsh onions grow
Only plantings by members who have set their locations are shown.
What people are saying about Welsh onions
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Who's planted Welsh onions
- Nadege Garden · Paris, France
- shiny back yard shaded garden · Wellington, NZ
- Spadix Big path patch
- Skud Ballarat backyard, zone 1 · Ballarat, Victoria,...
Welsh onion harvests
-
shiny harvested not specified.
over 6 years ago
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shiny harvested 5 .
over 6 years ago
-
shiny harvested not specified.
almost 7 years ago
shiny harvested not specified.
Find Welsh onion seeds
View all Welsh onion seeds
- Purchase seeds via Ebay
- Sign in or sign up to list your seeds to trade.
Ecological requirements
Data from the FAO EcoCrop database for Allium fistulosum L.
| Family / Taxonomy | Liliopsida Liliidae Asparagales Alliaceae |
|---|---|
| Optimal temperature | 12 - 25 °C |
| Absolute temperature | 6 - 30 °C |
| Optimal rainfall | 850 - 1600 mm/year |
| Absolute rainfall | 700 - 2500 mm/year |
| Optimal soil pH | 6.6 - 7.4 |
| Absolute soil pH | 5.5 - 8.5 |
| Crop cycle | 60 - 160 days |
| Max altitude | 2000 m |
| Life form | herb |
| Life span | annual, perennial |
| Habit | erect |
| Optimal soil depth | medium (50-150 cm) |
| Optimal soil texture | medium, organic |
| Optimal soil fertility | high |
| Optimal soil drainage | well (dry spells) |
| Optimal soil salinity | low (<4 dS/m) |
| Photoperiod | short day (<12 hours), neutral day (12-14 hours), long day (>14 hours) |
| Optimal light | clear skies |
Learn more about Welsh onions
Resources outside Growstuff.
