Allium
Welsh Onion
Allium fistulosum
Clumping perennial spring onion — never need to sow again.
Full to partial
Moderate
Average
Very easy
Yes
Stems & leaves
Perennial
Hardy
5 L
15 cm
Root
Carrot
Welsh onions mask carrot scent from rust fly while their onion compounds suppress soil-borne pathogens.
Vegetable
Tomato
Welsh onion's sulfur compounds deter aphids and spider mites from tomato foliage while sharing similar water needs.
Fruit
Strawberry
Welsh onions deter spider mites and slugs threatening strawberry foliage and fruit.
Situations where this plant is a reliable fit — from someone's kitchen sill to a wind-blown rooftop.
Balcony
A few pots on a flat outdoor perch — some sun, some wind.
Ladder planter
A tilted step-ladder with a shallow tray on each rung — sun-facing, five tiers of herbs, salad and strawberries in the footprint of one pot.
Wooden crate
A shallow wine or veg crate lined with hessian — perfect for salad and shallow-rooted herbs.
Raised bed
A traditional plot or timber-sided bed — deepest root run, widest planting choice.
Water jar
A jam jar of water on the sill — no soil at all. Regrow from kitchen scraps.
Root in water, transfer to soil
7 days
★★★★★
Yes
How to do it
Same as spring onion — stand the rooted base in 1 cm of water, refresh every 2 days, snip green tops as they appear.
What to expect
Indefinite indoors; perennial once moved to soil.
Honest note
Hardier than spring onion — survives outdoors year-round once planted.
Where to source
Get growing in United Kingdom
Shop local first
The best plants come from a real nursery, and the best trowel comes from the old-fashioned ironmonger down the road — people who know their stock and can advise. Try local first, both for the plant and the kit. It keeps small growers and small hardware shops alive.
Searching near London
For pots, compost, seed trays, twine and other kit — Amazon has the essentials if the local option isn't right. Not a plant nursery; use the local map above for the plant itself.
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