When to plant Onions in Brighton

Allium cepa

Onion
Onion · Allium cepa

A hardy allium for UK gardens, grown from sets. Plant spring sets for a summer crop, or named overwintering sets in autumn for an earlier lift. It needs free-draining soil, steady weeding, and a careful cure before storing.

45 cm · Full Sun · Moderate Water

Add to garden

Calibrated to Brighton · last frost ≈ 10 Apr

Plant out September to October, harvest June to September. Frost risk November to April.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Plant outNoNoNoNoNoNoNoNoYesYesNoNo
HarvestNoNoNoNoNoYesYesYesYesNoNoNo

Growing guide

What to do through the growing season

Growing guide for

Change the guide to see different planting timelines and tips.

Plant named overwintering sets in free-draining soil for an earlier crop. Do not use spring sets.

  1. 01

    Prepare the Bed

    2 Sept to 16 Sept

    Prepare the bed around 2nd September - 16th September. It must drain freely. Work in garden compost or well-rotted organic matter. Do not add fresh manure.

  2. 02

    Plant Overwintering Sets

    16 Sept to 28 Oct

    Plant named overwintering sets around 16th September - 28th October, tips just showing. Do not plant spring sets. Space apart, in rows apart. Firm the soil. Water if it is dry.

    • In a mild town, wait until the soil is cooling. Too much autumn leaf can raise the risk of bolting in spring.
    • Birds lift sets. Cover with fleece or mesh until they root.

  3. 03

    Keep Weed Free

    16 Sept to 15 Jun 2027 Dates as each sowing reaches this stage

    From 16th September to 15th June 2027, keep weeds down. Hand-weed close to the bulbs. Water in dry spells once growth restarts, then ease off when the leaves begin to yellow.

  4. 04

    Lift and Cure Bulbs

    23 Jun to 23 Sept 2027 Dates as each sowing reaches this stage

    Lift bulbs through 23rd June - 23rd September 2027, when the tops yellow and fall over. Dry them somewhere warm and airy for two to three weeks, then trim the roots and loose tops before storing.

Suggested varieties

Popular varieties of Onion to consider

Sturon

A dependable maincrop onion with good storage qualities and firm, globe-shaped bulbs.

Red Baron

A reliable red onion with good colour and a steady crop from sets or transplants.

Senshyu Yellow

A well-known overwintering onion that can be planted in autumn for an early summer harvest in mild UK gardens.

Centurion

A widely grown, high-yielding set onion with good tolerance to bolting.

Onion guides by town

See how Onion timing shifts in other towns with different frost dates.