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Vegetable

Spring Onion

Allium cepa

Spring onions are versatile and easy to grow. They are typically harvested when young and used as salad onions or scallions. If left to mature, they develop into bulb onions suitable for both raw and cooked preparations.

Spring Onion

Quick Information

Height
30cm
Sun
Full Sun
Water
Moderate Water

Planting Calendar

Seed DirectNot Active
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MaintenanceActive Now!
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HarvestNot Active
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Growing Guide for

1
Sow Seeds (Spring/Summer)

31 Mar 2025 - 13 Jul 2025

Sow seeds 1-2cm deep. For individual onions, sow thinly in rows. Alternatively, for easy bunch harvesting like supermarket onions, sow 6-8 seeds together in clumps spaced about 10-15cm apart. Sow successionally every 2-3 weeks for continuous supply.

For easy harvesting in bunches, sow 6-8 seeds together in each hole (multi-sowing).
Space multi-sown clumps about 10-15cm (4-6 inches) apart to give each bunch room to grow.
Whether sowing in rows or clumps, ensure the site has full sun and well-drained soil.

2
Water & Weed Regularly

10 Apr 2025 - Ongoing

Keep the area consistently moist, especially during dry spells, to ensure good growth. Remove weeds frequently as they compete strongly with young onions.

Water regularly at the base to keep soil moist, especially important for clumps sharing resources.
Carefully remove weeds by hand from around clumps or rows to avoid competition without disturbing roots.
A light mulch can help retain moisture and suppress weeds around both individual plants and clumps.

3
Thin Seedlings (If Sown Individually)

30 Apr 2025 - 15 May 2025

If sown thinly in rows (not clumps) and seedlings are overcrowded (closer than 2cm), thin them once large enough to handle. Thinning is usually unnecessary if seeds were multi-sown in clumps. Edible thinnings can be used in salads.

Thinning is generally not required when you have multi-sown seeds in clumps for bunch harvesting.
If you sowed thinly in rows and they are too dense, thin individual seedlings to about 2-3cm apart.
Use scissors to snip off unwanted seedlings at soil level if thinning rows, to avoid disturbing neighbours.

4
Harvest (Individual or Bunches)

30 May 2025 - 29 Jun 2025

Begin harvesting when onions reach pencil thickness (approx. 15cm tall), usually 8-12 weeks after sowing. Pull individual onions as needed (effectively thinning the row), or gently lift entire multi-sown clumps for harvesting as bunches.

For multi-sown onions, gently loosen the soil around the entire clump and lift it out as one bunch.
Harvest bunches when they reach your preferred size, similar to those bought in a shop.
Whether harvesting individuals or bunches, you can snip the green tops 2-3cm above soil for potential regrowth.

Suggested Varieties

Ishikura

Ishikura

Long, slender white stems with a mild flavour. Excellent for continuous harvesting. Doesn’t form a bulb.

£2.99 View
White Lisbon

White Lisbon

Fast-growing and reliable. Crisp, mild flavour. Can be sown successively for a long harvest season.

£2.99 View
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