
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.
Step-by-step instructions for growing Onion
Work the soil from 2nd February - 17th February, 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.
Plant sets from 5th March - 19th March, with the tips just showing above the soil. Space them apart in rows apart, then water in thoroughly straight away.
From 12th March to 10th July, 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.
Lift bulbs from 10th July - 9th August 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.
Tap a plant to see why it works (or doesn't) with Onion.
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.
Popular varieties of Onion to consider
A dependable maincrop onion with good storage qualities and firm, globe-shaped bulbs.
A reliable red onion with good colour and a steady crop from sets or transplants.
A well-known overwintering onion that can be planted in autumn for an early summer harvest in mild UK gardens.
A widely grown, high-yielding set onion with good tolerance to bolting.