Onion
Allium cepa
The backbone of the kitchen garden. Onions come in a wonderful range of shapes, sizes, and colours — round or oval, white, brown, or red — and there is a variety suited to almost every sowing season. Keep them clear of weeds and they will look after themselves.
SowingBoth methods
Sunlight☀️ Full sun
Water💧 Low
Days to harvest100–150
Soil pH6.5–7
Spacing10cm × 25cm
Planting Calendar
Sow indoorsSow outdoorsTransplantHarvest
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Sowing from Seed
Sow seeds under glass in midwinter, then move to a cold frame to harden off before planting out. In warmer weather, sow seeds thinly direct, 1cm deep in rows 25cm apart.Planting Sets
Sets (small bulbs) are the easier option for beginners — plant in rows 25cm apart with 10cm between each set, just covering the tip. Firm in well to prevent birds pulling them up.Thinning & Weeding
Thin seedlings to 10cm apart as they grow. Keep meticulously weed-free, as onions are poor competitors — weeds rob them of light and moisture.Soil: Well-drained, fertile soil. Avoid freshly manured ground.