Now is a good time to sow Spring Onion. Follow the sowing guide below.
Growing Calendar
This month: May
Log to journalStart seeds indoors this week
- •Fill tray with compost
- •Sow seeds evenly
- •Cover lightly with soil
- •Water gently
- •Place in warm light spot
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
Grown Organically
Every method in this guide works with natural systems — no synthetic chemicals, no shortcuts.
Read our approachCommon 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.
Member guides
There's more to growing Spring Onion than this guide covers.
Seasonal reminders, deeper guides, and the small adjustments that change a harvest.
