Onion Growing Guide

Allium cepa

Onion

Crop Rotation Group

Allium (Onion family) ●

Soil

Fertile, well-drained soil enriched with compost.

Position

Sun or partial shade.

Frost tolerant

Yes.

Feeding

Not normally required, though overwintered sets can be given a liquid feed in spring.

Spacing

Single Plants: 15cm (5") each way (minimum)
Rows: 10cm (3") with 20cm (7") row gap (minimum)

Sow and Plant

Start seeds in pots under cover in late winter before planting out in mid-spring, or grow from purchased sets (immature bulbs) planted in mid-spring.
Our Garden Planner can produce a personalized calendar of when to sow, plant and harvest for your area.

Notes

Japanese variety onion sets can be used to give an early harvest. Onion sets are also the better choice for heavier or wetter soils.

Harvesting

Harvest as soon as they reach a reasonable size. If storing them, wait until the tops start to die down and dry for about 10 days.

Troubleshooting

Weed early and often to keep onions growing strong. Seedlings are less likely to bolt (produce flowers) compared to bulb onions grown from sets.

Planting and Harvesting Calendar

< Back to All Plants