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Onion in the GardenTags plant encyclopedia

Allium cepa (Cepa Group)

 

Onion

Onions can be grown from seed or sets, (sets are immature onions, the size of marbles, grown the previous year, and they are less prone to mildew and onion fly). There are many varieties of onion, some red and some white. The older ones are often considered the best, Japanese varieties are getting more common and are planted/sown in the autumn to over winter and are often ready to harvest 4 to 6 weeks earlier than spring varieties.

Contributed by @WhispersMummy

 
plant Features
  • Onion likes full sun

    Full sun

  • Onion likes occasional watering

    Occasional watering

  • Onion is a little frost hardy: 32f (0°c)

    A little frost hardy: 32F (0°C)

  • Onion likes moist and free draining

    Moist and free draining

 
Similar plants are available to buy from 4 store(s) in the UK
 
plant information

Common name

Onion

Latin name

Allium cepa (Cepa Group)

type

Vegetable

family

Amaryllidaceae

ph

7.0 - 8.5 Acid - Neutral

  • Light

    Onion likes full sun

    Full sun

  • Frost

    Onion is a little frost hardy: 32f (0°c)

    A little frost hardy: 32F (0°C)

  • Soil

    Onion likes moist and free draining

    Moist and free draining

  • Water

    Onion likes occasional watering

    Occasional watering

Plant & bloom calendar

  •  
    Best time to plant
  •  
    When to harvest

full grown dimensions

The size of a fully grown Onion is 0.10meters x 0.30meters 0.10 M 0.30 M

Allium cepa (Cepa Group)

Onions can be grown from seed or sets, (sets are immature onions, the size of marbles, grown the previous year, and they are less prone to mildew and onion fly). There are many varieties of onion, some red and some white. The older ones are often considered the best, Japanese varieties are getting more common and are planted/sown in the autumn to over winter and are often ready to harvest 4 to 6 weeks earlier than spring varieties.


Propagation by seed indoors in Spring

From Early Spring TO Early Spring

Sow onion seed thinly in seed-trays or modules or direct in a prepared greenhouse border, in early Spring, ready to transplant to final positions in late spring.

 

Propagation by seed in late Summer

From Late Summer TO Early Autumn

For Japanese onions sow in final positions, in prepared beds, to establish themselves before the first frosts. Do not plant too early, because too much fresh growth will cause bolting (going to seed) next Spring. Aim for not more than three true leaves before frosts.

 

Planting outdoors in Spring

From Mid Spring TO Late Spring

Plant out to final positions in mid to late spring 6" between plants in rows 12" to 15 " apart, in prepared ground, limed to keep soil neutral to alkaline

 

Planting onion sets outdoors

From Early Spring TO Mid Spring

Plant out onion sets in early spring in well prepared beds, limed late in the previous year, 6" apart in rows 12" to 15" apart.

 
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