How to Harvest, Cure, and Store Onions

by Jack Grover
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Onions often take center stage in our culinary endeavors, their flavors enhancing our favorite dishes more than any other vegetable. More than just kitchen staples, onions are also friendly garden companions — easy to cultivate and versatile in use.

But the question of when to harvest onions is often subject to whether you prefer them as tender green onions or wish to store them for future culinary adventures.

Proper storage of onions begins with strategic variety selection, followed by harvesting at the right moment, meticulous curing, and careful storage under optimal conditions. This guide unravels the mysteries of these processes, ensuring that your onion harvest remains a flavorful addition to your meals for months on end.

When Are Onions Harvest-Ready?

Knowing when onions are ready to be plucked from the earth is crucial. Typically, onions take about three to four months after planting to reach maturity.

While it’s true that all globe onions follow a similar harvest-ready timeline, there are key signs to look out for to ensure you’re picking them at the perfect time. Midsummer is usually when the bulbs start packing on weight, and individual onions can be harvested as needed.

Learn More: How Many Onions Grow From One Bulb?

But how do you know when your entire crop is ready? There are three unmistakable signs:

  • tops flop over,
  • necks go soft,
  • leaves turn yellow or brown.

The key indicator that your onions are ripe for harvest is the falling over of their tops. Once these tops turn brown and fall over naturally, it’s a clear sign that your onions have stopped growing and are ready to be harvested.

This shift is not a sign of decay but rather a natural progression in the onion’s lifecycle. It’s an indication that your onions have reached maturity and are ready to be harvested.

However, don’t rush this process. It’s important that onions reach their full potential before you harvest them. If the tops haven’t fallen over yet, but you’re nearing the four-month mark, gently bend them over yourself. This will speed up the maturing process and allow for a complete harvest within one to two weeks.

Once the signs of readiness become evident, it’s essential to harvest your onions promptly to preserve their quality and enhance their storage potential.

Harvesting Onions from Your Garden

Harvesting onions is more than just yanking them out of the ground.

  1. Begin by using a garden fork to gently ease the soil around your onion plants. Be cautious not to pierce the onions in the process. If you’re blessed with loose soil, you might even be able to lift the bulbs by hand.
  2. Once you’ve carefully lifted them out of the ground, brush off any excess soil but avoid washing them as water can instigate rot during storage.
  3. Don’t remove their leaves. It’s best to keep the tops intact until the onions are fully cured. Prematurely trimming these tops could expose the neck of the onion, providing a gateway for bacteria and fungi to invade, leading to potential bulb rots.
  4. After harvesting, lay your onions out in a single layer in a shady spot with good ventilation for a couple of days. This allows any remaining soil to dry out and makes it easier for you to clean them before storage.

A word of caution: Any onions that have flowered won’t be ideal for storage. These blooming bulbs should be moved to the front of your culinary queue and used promptly.

How to Harvest Green Onions

Green onions, also known as bunching onions, unlike their traditional onion counterparts, lack a large bulb and are instead harvested young, boasting a milder flavor that adds a delicate touch to various dishes.

To harvest green onions, keep an eye on their height. Once the shoots stand approximately 6-7 inches tall, it’s time for the harvest. Delaying beyond this point could result in the plant becoming tougher and more challenging to pull from the ground. 

But what if you’ve missed this window of opportunity and your green onions have bolted, producing flower stalks? In such cases, immediately pull up the onion bulbs and plan to use them soon after harvest. While these late-bloomer onions will not store well, they can still be put to good use in your immediate culinary adventures.

Curing Onions

Much like other foods, curing onions is a critical step in readying them for long-term storage

During this process, the outer layers of the onion dry out and tighten around the bulb, forming a protective shell that helps maintain the onion’s freshness and firmness for an extended period.

As such, properly curing your onions is vital for their longevity. The objective here is to allow the exterior layers of the bulb to dry sufficiently so they can safeguard the interior from rot and mildew.

You can cure your onions outside during dry weather by laying them on top of the soil or any clean, dry surface. There’s no need to wash them — a simple brush-off of loose dirt will suffice.

However, be mindful not to expose your onions to excessive heat or moisture during this process. Mild warm and dry conditions are ideal for curing. If it’s sunny but not scorching, feel free to let them dry outdoors.

Overexposure to moisture or intense sun may result in decay or collapsed layers.

If outdoor conditions aren’t gratifying, move your onions into a garage, shed, or covered porch where they’ll be shielded from wet weather. Your chosen location should provide dry conditions and temperatures below 85°F over two to four weeks.

Also, ensure good airflow and ventilation — prop open doors and deploy fans if needed.

Your onions are well-cured when their outer skins dry out enough to rustle when handled. The necks should also be completely dry — you can check this by pinching the neck between your thumb and pointer finger; it shouldn’t feel slippery inside.

Once cured:

  • Give your onions a final brushing off of any remaining dirt and loose layers.
  • Trim the tops about an inch above the bulb (unless you plan on braiding them for storage), and pare down the roots.
  • Separate any damaged or insufficiently cured onions and use them immediately.

By following these practical steps, you can ensure your onions are well-prepared for long-term storage.

How to Store Onions to Last For Months

Once your onions have been successfully cured, they’re ready for storage.

While the ideal storage conditions for long-term preservation are 32°F with a relative humidity of 65 to 70%, achieving these exact parameters at home may prove challenging. Fortunately, onions are forgiving in nature.

Often, storing cured onions in a barn or garage where they can cool down in sync with the outside temperature is sufficient. However, avoid places with high temperatures or exposure to sunlight, as these conditions could trigger unwanted sprouting.

Your storage area should be well-ventilated. Storing onions on trays or in open bins can enhance airflow around the bulbs and allows for easy monitoring of their condition. It’s important to keep an eye out for any onions that start to deteriorate or sprout so you can remove them promptly.

Alternatively, consider storing your onions in mesh bags, wire baskets, or crates, or even braid them for hanging.

Whichever option you choose, regular checks are still vital, and any onions showing signs of rot should be discarded immediately.

One last piece of advice: Avoid storing onions near potatoes or apples. These produce companions give off high levels of ethylene gas — a natural plant hormone — that could trigger onion sprouting.

Learn More: When to Harvest Potatoes?

Best Onion Varieties for Storage

When it comes to storing onions, remember that variety matters. Some types of onions store better than others due to their lower water content and thicker skins.

The best storage onion varieties are those with a high sulfur content — the ones that bring tears to your eyes — and a robust flavor.

While mild or sweet onion variants may be tempting, they typically have a shorter shelf-life, often lasting only a few weeks.

Instead, Yellow onions like Copra, Stuttgarter Reise, or Patterson are excellent choices for long-term storage, often lasting up to eight months if properly cured and stored. Red Wing is also an excellent red onion variety known for its storage capacity.

Remember: Local conditions can significantly impact the growth of your onions. Therefore, it’s wise to consult with your local cooperative extension office to determine which types will thrive best in your area.


There’s something deeply satisfying about reaching into your pantry in December and pulling out an onion that you harvested back in the summer. Understanding when your onions are ready for harvest, how to cure them correctly, and how best to store them will ensure that you have this kitchen essential available year-round.

Remember that patience is paramount when dealing with onions — from waiting for their tops to fall over before harvesting right through curing and storing them appropriately. Choose high-storage varieties if you plan on extending their shelf life.

Now go forth, and let your garden (and your kitchen) reap the benefits of successfully harvested, cured, and stored onions!

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