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When to plant
onion sets in the UK
Push sets into the soil with the tip just showing. Easiest way to grow onions — skip seed unless you enjoy waiting.
Growing journey
20 weeks from sowing to harvest
Get onion sets seeds
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What onion sets need
Full sun. Well-drained soil. Birds will pull them up, so net early on.
Spacing
10cm between plants · 20cm between rows
Space evenly in rows. Thin seedlings early to avoid crowding.
Varieties to try
When to sow onion sets
Based on UK average frost date. Enter your postcode for exact dates, or find your city.
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Where to buy onion sets seeds
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What you'll need for onion sets
The stuff beginners wish they'd bought sooner.
Birds pull freshly planted sets straight out of the ground. Cover for the first 3-4 weeks until they've rooted properly.
Onions need 2 weeks of curing in air and sun after harvest. A wire rack lets air circulate underneath. An old oven shelf works too.
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Get your exact dates
Enter your postcode for personalised planting dates for onion sets.
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