One of the hardest parts of growing onions is knowing exactly when to harvest them. Pull them too early, and the bulbs may not reach their full size. Wait too long, and they may split, rot, or lose some of their storage quality.

Fortunately, onions give us several clear signs when they’re ready.

Whether you’re growing onions from seed, sets, or transplants, here’s how to know when it’s time to harvest your crop.

How Long Do Onions Take to Mature?

The exact number of days depends on the variety and how you started them.

Generally:

• Onion sets: 90–110 days
• Onion transplants: 100–120 days
• Onion seeds: 110–150 days

Some sweet onions mature earlier, while long-storage onions often take a little longer.

Instead of relying only on the calendar, it’s best to watch your plants for visual signs of maturity.

The Best Sign: The Tops Fall Over

The easiest way to know onions are ready is by looking at the leaves.

As onions mature:

• The leaves begin turning yellow.
• The neck softens.
• The green tops naturally bend over.
• Eventually, most of the foliage dries down.

When about 50–80% of the tops have naturally fallen over, it’s usually time to harvest.

The key word is naturally.

Don’t bend the tops over yourself. Years ago, gardeners believed this helped onions mature faster, but allowing the plants to finish on their own results in better bulb development and storage quality.

Check the Bulb Size

Another good indicator is the bulb itself.

The onion should have reached the expected size for its variety.

Keep in mind that different varieties naturally produce different-sized bulbs.

For example:

• Texas Grano develops large, sweet bulbs.
• Storage onions may be medium-sized but keep much longer.
• Shallots naturally remain smaller than bulbing onions.

Harvest During Dry Weather

If possible, harvest onions after several dry days.

Dry soil helps reduce:

• Rot
• Disease
• Mud sticking to bulbs
• Damage during harvesting

If rain is expected and most of your onions are mature, it may be worth harvesting before the weather turns wet.

How to Harvest Onions

Harvesting onions is simple but should be done carefully.

1. Loosen the soil around each bulb with a garden fork or hand trowel.
2. Lift the bulbs gently rather than pulling hard on the leaves.
3. Brush off loose soil.
4. Do not wash onions intended for storage.

Avoid bruising or cutting the bulbs, as damaged onions won’t store as long.

Should You Cure Onions?

Absolutely.

Curing is one of the most important steps if you want onions to last for months.

Freshly harvested onions contain a lot of moisture. Curing allows:

• The neck to dry completely.
• The outer skins to become papery.
• Small wounds to heal.
• Storage life to improve significantly.

Skipping this step often leads to early spoilage.

How to Cure Onions

Place harvested onions in a warm, dry, well-ventilated location out of direct sunlight.

Good places include:

• A covered porch
• A garage
• A shed
• A covered patio

Spread the onions in a single layer or place them on screens so air can circulate around every bulb.

Curing usually takes two to three weeks, depending on the humidity and weather.

They’re fully cured when:

• The neck is completely dry.
• The outer skin is papery.
• The roots are dry.
• The bulbs feel firm.

How to Store Onions

After curing:

• Trim the roots.
• Cut the tops to about 1 inch, or braid suitable varieties.
• Store onions in mesh bags, baskets, or crates with good airflow.
• Keep them in a cool, dark, dry location.

Avoid storing onions in plastic bags because trapped moisture encourages rot.

Also, don’t store onions right next to potatoes. Potatoes release moisture and gases that can shorten the storage life of both crops.

Harvesting Green Onions

If you’re growing onions for green onions or scallions, you don’t have to wait for bulbs to form.

Harvest them whenever the stems reach a usable size.

Green onions are best enjoyed fresh and don’t require curing.

What Happens If You Harvest Too Early?

Early-harvested onions are perfectly edible.

However, they may:

• Be smaller.
• Have thinner skins.
• Store for a shorter period.
• Continue drying unevenly.

They’re best used within a few weeks rather than stored for months.

What Happens If You Wait Too Long?

Leaving mature onions in the ground for too long can lead to problems such as:

• Split bulbs
• New root growth
• Rot during wet weather
• Sun damage
• Reduced storage life

Once most tops have naturally fallen over, it’s usually better to harvest rather than wait several more weeks.

My Experience Growing Onions

One of the best onion harvests I’ve ever had came from Texas Grano onions that I planted in the fall and protected with a frost cover through winter.

The following spring, they produced large, beautiful bulbs that far outperformed the onion sets I’d grown in previous years.

That’s one of the reasons I’m returning to Texas Grano again this season. While every year is different, that harvest reminded me how much timing, variety selection, and proper care can influence the final results.

Final Thoughts

Harvesting onions isn’t about picking a specific date on the calendar—it’s about paying attention to your plants.

When the tops begin yellowing and naturally fall over, the bulbs have reached their full potential and are ready to come out of the ground. Harvest them during dry weather, cure them properly, and store them in a cool, well-ventilated place to enjoy your homegrown onions for months.

Whether you’re growing sweet onions, storage onions, or shallots, waiting for the right harvest window is one of the simplest ways to improve both flavor and storage life.

Frequently Asked Questions

Should I bend onion tops over to make them mature?

No. Allow the tops to fall over naturally. Forcing them down too early can interrupt bulb development and reduce storage quality.

Can I harvest onions before the tops fall over?

Yes. Young onions can be harvested at any stage for fresh eating, but they won’t store as long because they haven’t fully matured.

How do I know if my onions are too late to harvest?

If onions begin producing new roots, split open, or show signs of rot after the tops have fallen, they were likely left in the ground too long.

Can onions stay in the ground after frost?

Mature onions can tolerate light frost, but prolonged cold, repeated freezing, or wet winter weather may reduce their storage quality. Harvest them once they are mature and the weather allows.

Do shallots harvest the same way as onions?

Yes. Shallots are harvested when their tops yellow and fall over naturally. After harvesting, cure them just as you would onions before placing them into storage.

Related Articles

• How to Grow Onions
• How to Cure Onions for Long-Term Storage
• How to Grow Shallots
• When to Harvest Garlic
• Best Vegetables to Plant in Fall
• How to Prepare Garden Beds for Fall Planting
• What to Plant in August (Zone 7 Guide)
• Why Fall Is One of the Best Gardening Seasons

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