Spring Onion

One of the fastest and most useful crops in the kitchen garden. Sow every few weeks and you'll have fresh spring onions continuously from spring to late autumn.

Written by Yemi · Last reviewed August 2026

Maturing this month

Great for kids

First sprouts in 7–14 days

Difficulty

Spring Onion should be ready to harvest this month. Check for size and colour.

Growing Calendar

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Sow

Transplant

Harvest

This month: Sep

Log to journal

Ready to harvest now

•Check size and ripeness
•Harvest regularly
•Store or use fresh

Sowing Guide

What you'd find on the seed packet

Sow Depth

1cm

Spacing

1cm in the row, 15cm between rows

Germination

7–14days

Thinning

No thinning needed: sow at final spacing and harvest whole plants

Grower's Note

Sow thinly to avoid overcrowding. A small patch sown every 3 weeks from March gives a continuous supply with very little effort.

Recommended Varieties

'White Lisbon' holds an RHS Award of Garden Merit and is the reliable old favourite, good for both summer sowing and overwintering. 'Apache' also holds an AGM, with purple-skinned bulbs and a mild flavour, and grows fast enough to suit containers.

Planting Out Guide

Best spaces, conditions and how to plant out

Plant Spacing

2–5cm (in rows 10cm apart)

Best Grown In

Raised beds, containers, open ground

Conditions

Full sun to partial shade. Fertile, free-draining soil. Sow or plant successionally for a continuous supply.

Grower's Note

Can be planted as modules or sown direct. Harvest when bulbs are pencil-thick for the best mild flavour. Leave longer for a stronger taste.

Growing Stages

Approximate weeks from sowing to harvest

Sprouting

1wks

Seeds germinate and first leaves emerge. Keep warm and moist.

Establishing

4wks

Root system develops and plant builds structure. Pot on if needed.

Maturing

4wks

Plant reaches full size and begins producing. Harvest at peak.

Total~9 weeksfrom seed to harvest

Companion Plants

Plant these nearby for natural pest control, better yields, and healthier soil.

Carrot

Repels Pests

Carrot's feathery foliage helps break up the scent trail pests would otherwise follow straight to Spring Onion.

Lettuce

Suppresses Weeds

Lettuce's low, spreading growth works as a living mulch, shading out weeds around Spring Onion.

Beetroot

Repels Pests

Beetroot's scent is thought to help mask Spring Onion from the pests looking for it.

Tomato

Repels Pests

Tomato's scent is thought to help mask Spring Onion from the pests looking for it.

Strawberry

Repels Pests

Strawberry's low, dense growth breaks up the pest-scent trail leading to Spring Onion.

Climate Control

Today

—C

Humidity

—%

Water

Every 3–4 days

Sunlight

6+ hours direct sun

Watch Out For

Onion fly maggots damage roots in early summer: cover with fine insect mesh from sowing to prevent egg-laying

Bolts in hot dry weather, particularly late-season sowings: keep well watered and sow bolt-resistant varieties for summer

White rot in the soil persists for many years: avoid growing in the same spot as other alliums if white rot has been a problem before

Pests & Problems

Full guide

Onion Fly

Wilting seedlings

May–Aug

Allium Leaf Miner

White flecks in a line on leaves

Mar–Apr & Oct–Nov

White Rot

Yellowing leaves

Apr–Jun

What You'll Need

Equipment for growing spring onion

Modular Seed Tray

96-cell for precision sowing

Fine Rose Watering Can

Gentle shower for seedlings

Bamboo Canes

Pack of 20 × 120cm

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Grown Organically

Every method in this guide works with natural systems: no synthetic chemicals, no shortcuts.

Read our approach

Common Questions

About growing Spring Onion in the UK

How quickly do spring onions grow?

Spring onions are one of the fastest crops in the garden: ready to harvest in 8–12 weeks from sowing. Sow every 3 weeks from March to August for a continuous supply throughout the season.

Can spring onions be grown indoors?

Yes, spring onions grow well on a sunny windowsill. Sow densely in a deep container or window box. Harvest as needed and resow for a continuous indoor supply. They need minimal space and good light.

What is the difference between spring onions and salad onions?

Spring onions and salad onions are the same thing: small, immature onions harvested before the bulb fully develops. The terms are used interchangeably. Welsh onions and bunching onions are similar but slightly different plant species.

Do spring onions grow back after cutting?

Yes, if you cut spring onions above the white part and leave the roots and base in the ground (or in water), they will regrow. This works best with store-bought spring onions placed in water. Garden plants regrow similarly if the bulb base is left intact.

Written from real growing experience, not just research. Read the story behind Pelham Gardens.

Member guides

There's more to growing Spring Onion than this guide covers.

A Garden Journal to log what worked, a personalised sowing planner in My Garden, and monthly reminders timed to the calendar.

See what's included