How to Store Onions Long Term
Knowing how to store onions long term is just as important as growing them well. Even the best onions won’t last if they’re stored incorrectly, while properly cured onions can keep for months.
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🥬 Seed Trays & Propagation Kits
Keep growing through autumn by starting suitable hardy crops under cover.
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⭐ Recommended Products — 🧅 Onions (Seeds, Sets & Storage Essentials)
Onions are a staple crop for gardens and allotments — easy to grow and brilliant for long-term storage when done right.
• Onion Sets (Spring & Autumn Planting)
Small starter bulbs that are quick and reliable to grow — ideal for beginners and perfect for strong, consistent harvests.
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• Onion Seeds (Wide Variety Selection)
Great if you want more choice, larger crops, or specific varieties for cooking or salads — cost-effective and ideal for early sowing under cover.
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• Onion & Vegetable Feed (Balanced Fertiliser)
Specially formulated fertiliser to support healthy leaf growth and strong bulb development — apply during the growing season for better yields.
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• Onion Storage Bags (Breathable Mesh Sacks)
Allows airflow while storing harvested onions — helps prevent rot and keeps bulbs fresh for months.
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• Onion Drying Rack / Harvest Storage Crate
Perfect for curing onions after lifting — improves longevity and ensures proper drying before storage.
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This guide explains how to prepare onions for storage, the best storage conditions in the UK, and common mistakes that cause onions to spoil early.
Why Proper Onion Storage Matters
Correct storage helps onions:
- Last through autumn and winter
- Retain flavour and firmness
- Avoid rot and mould
- Reduce waste
Storage success begins before onions even leave the ground.
For a full growing overview, see ONION SETS UK: THE COMPLETE GUIDE TO PLANTING, GROWING & HARVESTING ONIONS.
Harvest Timing Affects Storage Life
Onions store best when they are:
- Fully mature
- Harvested at the right time
- Properly dried before storage
Harvesting too early or too late reduces storage life.
If you’re unsure when to lift your onions, see WHEN ARE ONIONS READY TO HARVEST IN THE UK.
How to Cure Onions Before Storage
Curing is the process of drying onions so they store properly.
To cure onions:
- Harvest on a dry day
- Lay onions out in a single layer
- Leave them to dry for 2–3 weeks
- Ensure good airflow
- Keep them out of rain
Leaves and necks should feel dry and papery before storage.
Should You Wash Onions Before Storing?
No — onions should never be washed before storage.
Washing:
- Introduces moisture
- Encourages rot
- Shortens storage life
Simply brush off loose soil once onions are dry.
Best Conditions for Storing Onions
Onions store best in:
- A cool place
- A dry environment
- Good ventilation
- Darkness or low light
Ideal storage locations include:
- Sheds
- Garages
- Pantries
- Well-ventilated cupboards
Avoid storing onions in plastic bags, which trap moisture.
How Long Do Onions Store?
Storage life depends on variety and conditions.
- Storage onions: Several months
- Mild or salad onions: A few weeks
- Damaged onions: Use immediately
Choosing the right variety helps. See BEST ONION VARIETIES FOR UK GARDENS for storage-friendly options.
Should You Cut the Leaves Off Before Storage?
Yes — once onions are fully cured:
- Trim leaves back to around 2–3 cm
- Remove loose outer skins if needed
- Avoid cutting too close to the bulb
This reduces the chance of rot entering the bulb.
Common Onion Storage Problems
Onions Going Soft
Usually caused by:
- Poor curing
- High humidity
- Warm storage conditions
Mould or Rot
Often caused by:
- Damage during harvesting
- Storing damp onions
- Poor airflow
If onions bolt or split, they won’t store well. See WHY ONIONS BOLT AND HOW TO STOP IT for prevention tips.
Can You Store Onions in the Fridge?
Whole onions should not be stored in the fridge.
Fridges are:
- Too humid
- Likely to soften onions
Once cut, onions should be refrigerated and used within a few days.
What to Do With Onions That Won’t Store
Some onions are better used fresh.
Options include:
- Cooking
- Freezing
- Preserving
Pickling is a great option for surplus onions. See PICKLED RED ONION RECIPE for an easy method.
Summary: How to Store Onions Long Term
- Harvest at the right time
- Cure onions thoroughly
- Store in a cool, dry, ventilated place
- Avoid washing before storage
- Use damaged onions first
For everything you need to know about growing and using onions successfully, return to ONION SETS UK: THE COMPLETE GUIDE TO PLANTING, GROWING & HARVESTING ONIONS.
Related Onion Growing Guides
- WHEN TO PLANT ONION SETS IN THE UK
- BEST ONION VARIETIES FOR UK GARDENS
- WHY ONIONS BOLT AND HOW TO STOP IT
- HOW TO GROW ONIONS IN CONTAINERS
- PICKLED RED ONION RECIPE