Onions in Garmond

Allium cepa

Onion
Onion · Allium cepa

A hardy allium for UK gardens, usually grown from sets for the easiest crop or from seed for more choice. It needs free-draining soil, steady weeding and a careful cure before storing.

45 cm · Full Sun · Moderate Water

Add to garden

Calibrated to Garmond · last frost ≈ 24 May

Plant out May, harvest September to October. Frost risk September to May.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Plant outNoNoNoNoYesNoNoNoNoNoNoNo
HarvestNoNoNoNoNoNoNoNoYesYesNoNo

Growing guide

Step-by-step instructions for growing Onion

  1. 01

    Prepare the Bed

    9 Apr to 24 Apr

    Work the soil from 9th April - 24th April, making sure it drains freely and has a fine tilth. Mix in compost or well-rotted manure, but avoid fresh manure, which encourages soft growth and poorer bulbs.

  2. 02

    Plant Sets

    10 May to 24 May

    Plant sets from 10th May - 24th May, with the tips just showing above the soil. Space them apart in rows apart, then water in thoroughly straight away.

  3. 03

    Keep Weed Free

    17 May to 14 Sept every 3 weeks

    From 17th May to 14th September, hoe between rows lightly and hand weed close to the bulbs so they do not get crowded out. Water during dry spells while the bulbs are swelling, and keep the soil evenly moist rather than soggy.

  4. 04

    Lift and Cure Bulbs

    14 Sept to 14 Oct

    Lift bulbs from 14th September - 14th October when the tops yellow and fall over. Dry them in a warm, airy place for before storing, then trim off roots and loose tops once they are fully cured.

Companion plants

Tap a plant to see why it works (or doesn't) with Onion.

Good companions

Plants to avoid

Why companion planting matters

Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.

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.