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Onion sprite
VegetablesHardyBiennial

Onion

Onion is a staple bulb crop grown from seed, modules or sets for fresh use, drying and long storage. It is one of the backbone allotment crops, fitting easily into rotations and rewarding good ripening and curing with months of kitchen use.

Basic information

Category
Vegetables
Lifecycle
Biennial
Hardiness
Hardy
Planting partners
16 companions · 8 crops to avoid

Growth profile

Days to harvest
100 days
Germination window
7–14 days
Germination temperature
10–30 °C
Plant spacing
10 cm
Row spacing
30 cm
Sowing depth
1.5 cm
Height
45 cm
Spread
10 cm

Calendar

J
F
M
A
M
J
J
A
S
O
N
D
Sow Indoors
Sow Outdoors
Plant Out
Flowering / Harvest
Timings based on average frost dates in the UK. Sign up to set your frost dates.

Care tips

Grow onions in full sun on free-draining fertile soil, and avoid excessive nitrogen that encourages lush soft growth at the expense of good bulb keeping quality. Weed carefully, water while bulbs are forming, then dry and cure thoroughly before storing.

Common pests

Onion fly, downy mildew, thrips, white rot.

Companions

Beetroot spriteBeetrootBrussels Sprouts spriteBrussels SproutsCabbage spriteCabbageCarrot spriteCarrotCauliflower spriteCauliflowerChard spriteChardKohlrabi spriteKohlrabiLeek spriteLeekLettuce spriteLettuceParsnip spriteParsnipPerpetual Spinach spritePerpetual SpinachRed Cabbage spriteRed CabbageSavoy Cabbage spriteSavoy CabbageSpring Cabbage spriteSpring CabbageSwede spriteSwedeTurnip spriteTurnip

Don’t grow with

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