When to Harvest Onions (How to Tell When They Are Ready)

There’s a point in every growing season when you start staring down your onion patch, wondering… is it time?

Maybe the tops are falling. Or maybe just a few are. Some leaves are yellowing, but the bulbs don’t look big enough. And what’s with that one plant already flowering?

Yeah – figuring out when to harvest onions isn’t as simple as waiting for the tops to flop. There’s way more going on underground (and just above it) than most folks realize.

And truth is, if you get it wrong – if you pull too early or wait too long – you could end up with stunted bulbs, rot, or onions that just don’t last.

In this article, we’re digging into the actual, observable signs that your onions are truly mature – leaf by leaf, neck by neck.

Understanding Onion Growth and Maturity

You can’t know when to harvest if you don’t first understand what your onions are actually doing underground.

What Triggers Bulb Formation

It’s not size. Or time. It’s day length. Onions are photoperiod-sensitive, which basically means the length of daylight tells them when to stop growing leaves and start swelling bulbs.

Long-day varieties need about 14–16 hours of daylight. Short-day ones start bulbing with just 10–12 hours.

That’s why planting at the right time for your region matters so much. Plant too late, and the bulbs don’t have enough time to size up before the daylight peaks.

Plant too early, and they might start growing leaves in cold soil, then bolt when it warms up.

Leaf Count as a Maturity Indicator

Now here’s something most folks miss: the number of leaves matters.

Each hollow leaf your onion sends up corresponds to a ring in the bulb. Seven leaves? Expect seven rings. Thirteen? That’s your maximum – your “perfect” onion.

But not all varieties hit that number, and that’s okay. Once your onions have at least 7 solid leaves, you can start paying closer attention.

More leaves usually means a larger bulb potential. But again, it’s not just about quantity – it’s how mature and healthy those leaves are.

How Leaf Development Reflects Bulb Structure

Watch the progression. The oldest leaves start drying first, and that maturity works its way up. That last leaf – the one that came out most recently? That’s the key.

It needs to be fully dried before you pull the onion. Otherwise, moisture can get trapped inside the neck, and… well, rot.

The neck itself (where the leaves meet the bulb) tells you a lot.

Once the plant is done transferring all its energy to the bulb, the neck starts to soften. That’s a good thing. It means the onion’s ready. If it’s still thick and stiff, wait.

Key Signs Your Onions Are Ready to Harvest

You could guess. Or you could watch for the signs your plants are already giving you. They're subtle but solid. Here’s what matters.

The Soft Neck Test: Final Carbohydrate Transfer

This one’s huge.

Right above the bulb, where the leafy stalks merge into the neck – press it gently between your fingers. If it still feels stiff or thick, the plant’s still pushing energy into the bulb. Give it more time.

But once the neck goes soft, that means the plant has finished transferring carbohydrates from the leaves down into the rings. It’s done bulking up. Harvest time is close.

Dryness of the Last Leaf and Neck Cavity Check

Most people focus on the tops falling, but here’s a more precise clue: the youngest leaf—the last one that emerged – should be completely dry.

That’s because onion leaves dry from oldest to youngest. Pulling before that last leaf dries? Risky.

Moisture from that live leaf can seep into the neck cavity (the little space at the top of the bulb), making it soft or sunken. And that’s prime rot territory.

Neck Roll Test: Confirming Readiness

This one’s oddly satisfying.

Gently roll the neck between your fingers. If it feels tight, with no slippery or sliding layers, the bulb is ready. If it squishes or shifts under your fingers, wait a few more days. That looseness means the internal structure isn’t sealed yet.

Takes five seconds, but it’s surprisingly accurate.

The 80% Top Drying Rule

Here’s a good rule of thumb: when around 80% of your onion tops have dried up and fallen, that’s your window.

Don’t wait for 100%. Some bulbs mature faster than others, and waiting too long can mean the early ones go over – starting to rot or even push up flowers if you grew from sets. You’ve got about two weeks once most tops are down. Use that time wisely.

When the Tops Fall Over: What It Really Means

Yes, top fall is a signal but it’s not the only one.

Some varieties won’t fall over cleanly. And sometimes, tops bend from wind or watering, not maturity. So if you’re only waiting for flopped foliage, you’ll miss better cues.

It’s a piece of the puzzle, not the whole picture.

Timing Considerations for Different Purposes

Not every onion harvest looks the same. It all depends on what you plan to do with them. Eat them now? Store them for months? Different goals, different timing.

For Immediate Use: Early Harvest Based on Top Fall

If you’re just grabbing a few onions for dinner, you don’t have to be picky.

Once some of the tops have flopped and the skins have started to dry a bit, you’re good to pull one or two. They’ll have enough green tops to shield the bulb from sunscald during curing, and flavor-wise, they’re already decent.

This isn’t your storage harvest – it’s your “we need onions tonight” harvest.

For Storage: Waiting for Full Maturity

This is where patience pays off.

For onions you want to store through the fall or winter, wait until all the signs line up: soft neck, dry last leaf, 80% tops down. Pulling too early means moisture still inside the bulb, which is just an open invite for mold, soft rot, and weird smells a few weeks down the line.

These are the onions you handle like treasure. Because they’re going to sit in your pantry for a while.

Manual Top Bending to Trigger Curing

Now, sometimes the onions are clearly done bulbing but those tops just won’t fall on their own.

If that’s the case, and only then, you can go ahead and bend the tops over by hand. That little move sends a signal to the plant: you’re finished here. It kickstarts the curing process and helps seal the neck.

But don’t do this while the plant’s still actively growing. Bending green, working tops cuts off energy transfer, leading to smaller, underdeveloped bulbs. Timing is everything.

Harvest Timing for Green Onions

Whole different ballgame.

Green onions (those bunching types) aren’t waiting for full bulbs. You’re pulling them young, when they hit around 6 or 7 inches tall. Nice and crisp. If they bolt (throw up a flower stalk), you’ve missed peak flavor. Yank them and use them right away. Don’t bother storing.

Day Count Guidelines: 100–125 Days After Planting

If you like numbers, here’s your benchmark: most full-size bulb onions hit maturity somewhere between 100 and 125 days after planting.

But don’t treat it like gospel. Weather, soil health, and variety all mess with the clock. Use it as a guide but let the plants tell you the truth.

Environmental and Practical Timing Factors

Sometimes, the signs from the plant aren’t the only thing to consider. Timing your harvest also means paying attention to the weather, the time of day, and the bigger picture in your garden.

Best Time of Day to Harvest: Morning Benefits

Morning is your best bet.

Not because onions care what time it is but because you do. Harvesting in the morning means cooler temps, less direct sun, and less stress on the bulbs.

You’re not cooking them on the ground while you work. Also, you're less likely to bruise them in the rush to get out of the heat.

So unless it’s been raining, try to plan your harvest early in the day. Your onions will appreciate the gentler handling. So will your back.

Weather Conditions: Importance of Dry Harvest

This one’s big. Dry weather matters – a lot.

Harvesting onions from wet soil, or during humid spells, makes everything trickier. The moisture clings to the bulbs, gets into the necks, and gives fungi and bacteria a perfect environment to settle in.

Even just a light drizzle can make a mess of an otherwise clean harvest. Wait for a clear, dry day with soil that isn’t soggy. You want those onions to come up clean, not caked in mud.

Why Not to Wait for Every Plant to Mature

Don’t wait for the last stragglers.

In every batch of onions, some will mature earlier than others. If you sit around waiting for every single top to fall over, you risk over-maturing the early ones.

That’s when they start going soft or even push up flowers. Especially with onions grown from sets, which are a bit more eager to bolt.

When the bulk of the crop is ready (say 80%) it’s time. Start pulling. The rest will catch up, or you’ll pull them as needed.

Harvest Deadline After Tops Dry

Once those tops dry down, the clock starts ticking.

You’ve got about two weeks. That’s your window. Leave them in the ground any longer, and things start to go sideways – especially if it rains or if temps swing too much.

The bulbs are vulnerable now. They’ve stopped growing, but they haven’t been cured. That limbo is when rot and sprouting risks shoot up.

So don’t dawdle. If you see dried tops and soft necks – go.

Harvest Onions with Confidence!

There’s no single “perfect” moment to harvest onions. But there are reliable signs – ones you can see, touch, and feel – that tell you when it’s time.

It starts with the leaves. At least seven, and ideally more. Then the neck softens, the last leaf dries, and most of the tops fall over. That’s your signal. Add in the neck roll test and dry weather timing, and you've got yourself a solid plan.

And remember – what you plan to do with your onions matters. Quick meals? You can pull them a little early. Long storage? Wait for full maturity, and don’t rush the harvest once tops dry.

Don’t overthink it, but don’t wing it either. Watch the plants. Trust what they’re showing you.

Frequently Asked Questions (FAQs)

How many leaves should an onion have before harvesting?

At least seven. Each leaf corresponds to a ring in the bulb. More leaves generally mean a bigger, more developed onion.

Is it okay to harvest onions before all the tops fall?

Yes. You don’t need to wait for every top to flop. When about 80% have fallen and other signs of maturity are showing, it's time.

What happens if I wait too long to harvest?

Over-mature onions can start to rot in the ground or go to seed, especially if grown from sets. The storage quality also drops.

Can I bend the tops if they’re not falling over naturally?

Only if the onions are done bulbing. Bending too early cuts off energy transfer and can shrink the bulbs.

Why does harvesting in dry weather matter?

Wet conditions make onions more prone to rot and disease. Dry weather keeps bulbs clean and helps them cure properly.