How to grow Spring onions in the UK
Skinny mild onions that fit in any gap or pot.
- DifficultyEasy peasy
- WhereBeds or Pots
- Grows to30cm
- Spacing2cm
- Time to first pickabout 8 weeks
When to sow, plant and harvest spring onions
| Sow indoors | mid February to early July |
|---|---|
| Sow outdoors | early March to late July |
| Plant out | early April to mid August |
| Pick | mid May to late October |
Dates are for central England. Sow about two weeks later in the north and Scotland, and up to two weeks earlier in the south and south west. Get the dates for your postcode.
Starting it indoors
- Fill a small pot or tray with seed compost
- Push the seeds in (1cm deep) - a couple per pot
- Water gently, then put them on a bright windowsill
- Keep the compost damp but not soggy - check it every day
- When they have 2 proper leaves, give each seedling its own pot
Sowing it outdoors
- Pull out any weeds and rake the top of your bed until it's crumbly, like cake crumbs
- Make a little line in the soil (1cm deep) with your finger or a stick
- Drop the seeds in, about 2cm apart in the row, with rows 15cm apart
- Gently cover them with soil and pat it down
- Water with a watering can that has a sprinkler head
- Push in a label so you remember what's there
Planting it out
- Toughen them up ('hardening off'): put them outside in the day for a week, bring them in at night
- Dig a hole a bit bigger than the pot
- Tip the plant out gently, holding the leaves, not the stem
- Pop it in the hole, firm the soil around it, and water well
- Space the plants about 2cm apart in the row, with rows 15cm apart
Top tips for growing spring onions
- Sow a pinch every 3 weeks for a steady supply.
Soil and feeding
Well-drained soil that doesn't stay wet. Add compost, and grit if your soil is heavy clay - onions and garlic rot if they sit in water. No fresh manure.
Pests and problems
- Allium leaf miner: a tiny fly whose maggots tunnel into onion-family stems in spring and autumn
- Slugs & snails: munch seedlings overnight, worst in wet weather
- Cover with fine insect mesh (like 'Enviromesh') on hoops - the holes are too small for flies and butterflies
- Bury or weigh down the edges so nothing can crawl underneath
Harvesting and eating spring onions
Pull them when they're as thick as a pencil.
How to eat them: Chop into scrambled eggs or noodles.
Storing spring onions
Keeps about 1 week.
- Keep in the fridge, or stand the roots in a glass of water
Chop and freeze in a bag - great sprinkled into cooking straight from frozen.
Good varieties of spring onions
- White Lisbon: The classic - quick and reliable.
- Apache: Deep purple-red stems.
Companion planting
Grows well with
- Carrots: the onion smell hides carrots from carrot fly
Keep away from
- Peas: the onion family can stunt peas
- French beans: the onion family can stunt beans
- Runner beans: the onion family can stunt beans
Saving your own spring onions seed
It only makes seed in its second summer.
- This plant flowers in its second year, so leave one or two strong plants in the ground over winter
- Next summer they grow tall and flower - bees love them
- Cut the seed heads when they're brown and dry, and shake out the seeds
- Cabbage-family plants cross with each other, so seed may not come true
Things to build for spring onions
Where to buy spring onions seeds
Thompson & Morgan · Suttons · Amazon
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Spring onions questions
When should I sow spring onions in the UK?
In the UK, sow spring onions indoors from mid February to early July or outdoors from early March to late July. These dates suit central England; sow about two weeks later in the north and Scotland and up to two weeks earlier in the mild south and south west.
When do I plant out spring onions?
Plant spring onions out from early April to mid August.
When can I pick spring onions?
Spring onions is ready from mid May to late October. Pull them when they're as thick as a pencil.
How long do spring onions take to grow?
Roughly 8 weeks from sowing or planting until the first harvest.
Are spring onions easy to grow?
Spring onions are rated 'easy peasy' for beginners, and can be grown in the ground or a raised bed or in pots and containers.
Plan your own garden: it tells you what to do and when, for your postcode.
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