This post contains affiliate links. As an Amazon Associate I earn from qualifying purchases. If you click a link and make a purchase, I may receive a small commission at no extra cost to you.
You should pick purple onions when the tops have fallen over and started to dry out, usually 100 to 120 days after planting.
Knowing when to pick purple onions is key to getting that perfect balance of sweetness and that signature sharp kick you love in salads and salsas.
If you’ve been wondering when to pick purple onions from your garden, you’re in the right place because timing truly makes or breaks your harvest.
Pull them too early, and you’ll get small, underdeveloped bulbs that won’t store well at all.
Wait too long, and your purple onions might start splitting, sprouting, or even rotting right in the soil.
In this post, we’ll dig deep into the exact signs that tell you when to pick purple onions, how to cure them properly, and common mistakes to dodge so your hard work pays off.
Let’s get growing.
When To Pick Purple Onions: The Key Signs To Watch
The best time to pick purple onions depends on a few clear visual and tactile clues that any gardener can spot.
Here’s what you need to look for before you even think about when to pick purple onions.
1. The Tops Fall Over Naturally
The most reliable signal for when to pick purple onions is when the green leafy tops flop over on their own.
This usually happens about two to three weeks after the bulbs have reached full size.
When about 50 to 80 percent of the tops have bent over, that’s your golden window to start harvesting.
Don’t force the tops down manually because that can trick you into thinking they’re ready when they aren’t.
Let nature tell you when to pick purple onions, and you’ll get bulbs that are firm and fully mature.
2. The Neck Softens and Dries
Another excellent indicator for when to pick purple onions is the condition of the neck, which is where the leaves meet the bulb.
Once that neck feels soft and papery instead of thick and juicy, your onions are starting to shut down for storage.
If the neck is still rigid and green, the onion is still actively growing, so hold off a bit longer.
Checking the neck is a foolproof way to decide when to pick purple onions even if the tops haven’t fully collapsed yet.
3. The Skin Shows Deep Purple Color
When to pick purple onions also becomes clear when the outer skin turns that rich, vibrant burgundy color you expect.
At full maturity, the papery skin will feel dry and rustle when you touch it.
If the skin still looks thin and pale, give your onions more time in the ground to develop that gorgeous hue.
A deep purple tone is a strong clue that the bulb is done sizing up and ready for harvest.
4. The Bulb Size Matches Your Expectations
You should also base when to pick purple onions on the actual size of the bulb relative to the variety you planted.
Most purple onion varieties are ready when they reach two to three inches in diameter.
Gently brush away a little soil from the top of the bulb to check its size without pulling it up.
If they’re still small but the tops are falling, that could mean they didn’t get enough water or nutrients early on.
In that case, you’ll just have to harvest smaller bulbs, but you’ll know better for next season.
5. Days to Maturity Have Passed
Checking your seed packet for the expected days to maturity helps you estimate when to pick purple onions from your region.
Typically, purple onions need about 100 to 120 days from transplanting or direct seeding.
Keep a garden journal or set a reminder on your phone so you don’t forget this crucial date.
While weather can shift things by a week or two, this timeline is a solid starting point for when to pick purple onions.
How To Harvest Purple Onions The Right Way
Once you’ve figured out when to pick purple onions, you also need to know how to lift them out of the dirt without causing damage.
Harvesting is easy, but a few gentle steps make a huge difference in how long your onions last.
1. Loosen the Soil First
Use a garden fork or a trowel to gently loosen the soil around each bulb before pulling.
This prevents you from snapping the roots or bruising the onion flesh.
If the ground is hard, water it lightly a day before you plan to harvest.
A little moisture makes the soil crumble away and allows for a clean lift.
2. Pull Gently by the Tops
Grasp the dried tops near the bulb and give a slow, steady tug upward.
Avoid yanking hard because that can tear the bulb and invite rot later on.
If a bulb resists, loosen more soil around it and try again.
Set each onion aside without stacking them too high to prevent bruising.
3. Leave Them in the Field to Dry
After you harvest, lay your purple onions right on the soil surface in a single layer.
Let them sit there for a day or two if the weather is dry and sunny.
This initial drying helps the outer skin tighten up and seals the neck tissues.
Just bring them inside if rain threatens because wet bulbs will not cure well.
Curing Purple Onions For Long Storage
Understanding when to pick purple onions is only half the battle because proper curing is what makes them last for months.
Curing is a drying process that turns the fresh bulb into a storage-ready onion.
Here’s exactly what you need to do after you’ve decided when to pick purple onions.
1. Pick a Dry, Shaded Spot
Move your onions to a well-ventilated area that’s out of direct sunlight, like a garage, shed, or covered porch.
Direct sun can scald the skin and cause uneven drying, which shortens their shelf life.
Spread them out on a wire rack, old window screen, or mesh bag so air circulates all around each bulb.
Ensure the space has good airflow to whisk away moisture and prevent mold from taking hold.
2. Let Them Cure for Two to Three Weeks
Leave your onions curing in that shaded spot for about two to three weeks.
You’ll know curing is done when the necks feel completely dry and tight, and the roots look shriveled.
The outer skin should be papery and peel easily without revealing any moisture underneath.
If you’re unsure, cut one open, a cured onion should feel firm and not squishy inside.
3. Trim and Store Properly
Once cured, cut the tops down to about one inch above the bulb and trim the roots close to the base.
Don’t wash your onions before storage because moisture invites rot and decay.
You can either braid the tops for hanging or place them in mesh bags, baskets, or crates.
Store your purple onions in a cool, dry, dark place with good air circulation, ideally around 40 to 50°F.
Common Mistakes When Picking Purple Onions
Even if you nail the timing for when to pick purple onions, a few slip-ups can ruin your entire crop.
Let’s run through the most frequent blunders so you can avoid them completely.
1. Leaving Them in the Ground Too Long
One of the biggest mistakes is ignoring when to pick purple onions and letting them sit far past maturity.
Once the tops have fully dried and fallen, the onions stop growing and just sit in the soil.
They may start growing again if rain returns, causing splitting or thick, woody centers.
They’re also more vulnerable to rot and pests the longer they stay buried.
Mark your calendar and check every few days once you get close to the predicted harvest date.
2. Harvesting on a Wet Day
Picking purple onions when the soil is soggy makes everything messier and riskier.
Wet onions hold excess moisture, and that moisture makes them rot during curing.
Always aim for a stretch of dry weather when you decide when to pick purple onions.
If you must harvest during damp conditions, dry them off quickly and cure them with extra ventilation.
3. Storing Onions Before They’re Cured
A huge shortcut is skipping the curing step and tossing fresh onions straight into your pantry or fridge.
Fresh onions have high moisture content that leads to rapid spoilage and mold growth.
Make sure you follow the full curing routine before moving them to long-term storage.
Patience during those three weeks will reward you with onions that last you all winter long.
So, When Should You Pick Purple Onions?
You should pick purple onions when the tops have flopped, the necks have softened, and the bulbs have reached a good size with deep purple skin.
Those signals usually pop up around 100 to 120 days after planting, so keep that timeline in mind.
If you’ve been wondering when to pick purple onions, just watch those signs and trust what your garden tells you.
Harvest gently, cure thoroughly, and store them in a cool, dry spot so they stay crisp and flavorful for months.
Now you’re fully equipped to get out there and pick purple onions at the perfect moment.