🧅
Onion
Allium cepa
Plant sets in spring, cure bulbs in late summer — a kitchen staple.
Sun
Full sun
Water
2.5 cm / week until bulbing
Soil
Fertile, well-drained, pH 6.0–7.0
Spacing
10 cm apart
Days to harvest
90–120 days
Hardiness
Zones 3–9
Seasonal Calendar
S
S
S
H
H
SH
S
JFMAMJJASOND
Sow Harvest
The method
- 1
Plant sets
Push sets into loose soil so just the tip shows, 10 cm apart.
- 2
Weed carefully
Shallow roots hate competition and hate being disturbed — hand weed.
- 3
Stop watering late
Cut back water when tops start to yellow — helps bulbs cure.
- 4
Cure
Lift, lay tops down in the sun for a week, then store somewhere dry and airy.
Common problems
Onion white rot
Long crop rotation (7+ years). Destroy infected plants — do not compost.
Bolting
Choose bolt-resistant sets and don't plant too early in cold soil.
Good neighbors
CarrotBeetLettuceStrawberry
Field tips
- “Small sets bulb better than large ones — big sets tend to bolt.”
- “Store only necked, papery-skinned bulbs; use the thick-necked ones first.”