When And How To Harvest Onions In Garden

Obviously, the first thing you need to know if you are to harvest onions is when are onions ready to be picked. Onions typically take 90 to 120 days to mature depending on their cultivar so if you aren't sure when exactly to harvest, you should also note the typical maturation date of your cultivars.

We cannot emphasize enough on knowing when do you harvest onions as it's crucial to avoid losing flavor or quality. Knowing when to pull onions up can be tricky especially if you're new so we'll walk you through the entire process especially if you're new to gardening, here's what to watch out for:

Yellowing Tops

Typically your onions will be ready to harvest when their tops, i.e. green stems begin to yellow and fall over. This occurs naturally and once this happens, it signals that the bulbs have reached their maximum possible full size. 

Now that you know the bulb has finished growing is matured and is no longer actively, obviously, you should be getting ready to harvest them. If you still harbor some doubts there are still a few more things that you can check.

Check Size

"What if I'm wrong?", "What if the yellow isn't actually yellow at all?", "How yellow does it need to be?", we've all been the fidgety nervous gardener once in the past so we know how it feels. Don't worry, the plants will tell you everything that you need to know about them once you know what to look out for.

If you're still unsure about when to harvest the onions after checking their yellowing, you can shift the topsoil and gently pull one onion to check the size of the bulbs and whether it is consistent with your cultivar. If the size is to your liking then harvest the rest of the onions, otherwise cover them with topsoil again, and allow them to continue growing.

Dry Leaves

If you are nervous about digging out the bulbs without damaging them, you can also check out their leaves. Once the bulbs mature, the leaves should start to dry out and become crispy, although you should harvest them when the leaves are dried until the halfway point.

Thus, if they still appear green, upright, and strong, don't harvest them obviously! The onions may still need some more time in the ground so give them a few more days to grow otherwise it may result in smaller bulbs that won’t store well.

Now you have been thoroughly educated and no longer need to ponder, "When are onions harvested?", you will still need to harvest the onions correctly and avoid any mistakes which could greatly impact their total storing time.

All right, so are you ready to learn how to pull them up? Here's what you will need and how to do it properly: 

Gather The Tools

After you have made absolutely certain that your onions are all completely ripe and mature, before you can start pulling them up you need to also make sure that you have all the right tools. This preparation phase is substantial and is often commonly neglected by novice gardeners. 

It's far too easy to damage your onion bulbs by pulling them out entirely by hand, you should get or invest in a good trowel and a garden fork in order to pull them out gently. Don't ignore the value of a good gardening glove to prevent any injuries as there's a risk of getting tetanus bacteria from the soil.

Loosen The Soil

Now before we can proceed to this next step you should harvest on a dry day after a period of no rain or check the weather forecast to ensure that there will be no rain during harvest otherwise, your onions will easily mold and rot during the storage stage. 

Gently work around the base of each onion with your gardening fork or trowel to loosen the soil, the onion bulbs are easily bruised so make sure to start digging from farther than you think the onion bulbs could be then work your way in. You don't want to accidentally skewer or pierce your onion which will ruin its storability. 

Pull The Bulbs

Once the onions are sufficiently loosened, you can either choose to pull up the onions by hand by grabbing them from the base and pulling them gently out of the soil. Make sure to not pull them out by pulling on their green top stems as it can cause the bulb to break.

Even if it doesn't, a fully intact stem is necessary to properly cure the bulbs and ensure maximum pantry life. If your onions are of more resistant variety then you can also opt for pulling the onions out by using the garden fork to lift them soil and all, then you can brush off the soil from the onions.

Inspect For Damage

I hate to be the guy to tell you this but no matter how perfectly you may have done everything or whether you did them all right, in the world or gardening there will always be some flawed or imperfect harvests as well as some plants having disease or damage.

If you want to get the good aspects of gardening, you also need to be willing to put up with the bad. So once you inspect the bulbs for any signs of disease and damage, discard any bulbs with soft or rotten spots as they might spread the disease to your healthy bulbs as well, but still all in all you shouldn't have too bad of a harvest.

Proper curing is critical for onion storage as the outer layers of the bulb need to be sufficiently dry and hard to protect the interior portion of the bulbs from any potential rot and mildew. 

That's not all though, not only is curing essential to prevent potential disease and spoilage, but it will also help your onions last longer in storage while also promoting better onion flavor. Here's how to dry onions i.e. cure the freshly harvested onions properly:

Remove Excess Dirt

First things first, any vegetable recently harvested tends to be dirty, and underground bulb plants such as onions are especially no exception. After harvesting, gently shake off any excess dirt from the onion bulbs but DO NOT wash them with water.

The introduction of any moisture can result in mold during the curing process which is also why we recommended harvesting them on a very dry day. After that you should start looking for a suitable well-ventilated area to cure them such as a shed, garage, or even a covered porch.

Leave Them For 2-3 Weeks

Once you've spread out your onions in a single layer to ensure maximum air circulation in a dry, warm, and well-ventilated shelter, you should leave them be for about 2-4 weeks depending on how large your bulbs are.

If you’re curing a large batch, then you can also tie the onions into bunches and hang them to cure effectively. However, make sure that the temperature of the place neither exceeds 90°F nor proceeds 75°F and use electric fans to introduce good ventilation if necessary.

Once the curing period is over, you can tell when your onions are well cured when the outer skin layers dry to the point of making a rustling sound when they're moved. Furthermore, the necks of onions should have dried down to the point they are completely closed off and you can pinch the neck between your thumb and index finger.

Also, if they're fully cured the tops shouldn't have any slippery sensation and the outer skin of the onions should feel papery and dry. If they aren't then it's probably not fully dried so allow them to cure for a little longer, every onion dries at a slightly different time.

After Curing

After curing the onions there are still a few more things to be done before you can store them and be done and over with once and for all. First, if any, brush off the remaining loose layers of dirt, yet again do not use water or moisture to clean your bulbs.

Cut the tops of your onions an inch or so above the bulb and trim their roots to make them compact for ease of storage unless you want to braid the onions. Check if any onions have failed to close their tops successfully and sort all the onions based on how well their tops were closed or if they were damaged as they won't store properly.

Once you have cured all the onions, you should sort and remove any onions that are too small, damaged, or failed to cure and close their tops sufficiently. This is because these onions will spoil first during storage and their spoilage will eventually spread to the unspoiled onions next to them until the entire storage is spoiled.

Okay, since we've gone and done that to get it over with, it’s time to store your onions for later use, however, keep in mind that this guide is incompatible if you want to learn how to store green onions.

Storage Location

Often, cured onions can be easily stored in these locations if they are available such as the barn, garage, root cellar, pantry, or basement guaranteed that they are cool, dry, and have lots of good air circulation. Ideally, the temperatures should hover somewhere between 32 to 36°F and the relative humidity at 65%. 

What you definitely shouldn't do is store the onions inside plastic bags or refrigerators as this can trap moisture and cause the bulbs to rot quickly. Additionally, you should also avoid any temperatures higher than 40°F as well as exposure to direct sunlight as this will trigger the onions to sprout into a new plant.

Check Bulbs Regularly

Despite having already gone through the hasslesome phase of curing and then sorting out all the bad onions, there is still a chance of some of the then perfectly good and healthy well-cured onions to show damage and eventually go bad during the extensive storing period.

Thus even while they are being stored you should regularly inspect all the onions in your storage to see if any of them have started to go bad and remove or consume them immediately depending on the type of damage so as to not have your entire onion stock be ruined by a single onion that's breaking bad.

Alternate Storage Methods

If you could not find any well-suited locations to store your onions then there are several more alternate options for you to try and carry out. You could either braid the onion stems together then hang them in a cool spot to store massive amounts of onions while taking a small area. 

If your braiding game isn't up to par then you can let technology cover you by purchasing some nets or mesh bags to hang the onions in a cool area while facilitating good air circulation to help the onions last longer. Last but not least, if you have any onions that are starting to go bad you can consider dehydrating or freezing them to use later.

Assuming optimal conditions and successful curing, the total time that your onions can last and stay good for depends on a variety of factors but also especially on the variety and the types of onions. Here is an idea of how long some onion varieties can last:

Red Onions

Red onions are the longest-lasting variety of onions but they also tend to be the most pungent with an extremely sharp peppery spicy flavor that can easily be tamed if you know how to caramelize onions. Some varieties such as the 'Red Wethersfield' can easily last as long as a year when kept properly in a dry and dark spot. 

Whereas the rest of them such as 'Redwing', 'Red Zepplin', etc will only keep for 6 to 10 months which is still significantly longer than any of the non-red onion varieties.

Yellow Onions

Yellow onions are great for sautées and stews but as expected they obviously last a lot shorter than red onions. However, fret not they are still the longest-keeping onions after the red onions. 

When stored properly in a cool, dry, and dark place, whole yellow onions such as 'Yellow Spanish' and 'Stuttgarter' have a shelf life of 5 to 6 months.

White Onions

Most white onions are softer and milder than red and yellow onions which makes their shelf life even shorter than the two. When stored properly, some white onion varieties like ‘Sterling’ and ‘Ringmaster’ can be stored for as long as 4 to 6 months.

But otherwise, you shouldn't usually white onions to last beyond 3 months under most circumstances.

Sweet Onions

Although sweet onions such as 'Vidalia' and 'Wala Wala' are also yellow onions, they contain fewer sulfurous compounds than other pungent onions and have higher sugar and water content which led to them being categorized as an entirely different category of onion. 

Furthermore, thanks to all of this and more along with having thin, papery skins have led to sweet onions having a significantly short shelf life. Sweet onions can barely last a month in the pantry, however, if wrapped in paper towels and stored in the crisper they might last up to 2 months. 

Most onions should not be stored in the refrigerator as the starch gets converted into sugar which turns the onion all mushy but sweet onions are high in sugar with little starchy content so they can handle the refrigerator just fine.

As the onions approach maturity, they start accumulating water and sugars in the bulbs by pulling the nutrients from the leaves. This causes the leaves to die back and the top to flop over which makes this a particularly good indicator of ripeness.

However, your onion bulbs should also likewise be decently sized and turn yellow in order to indicate the ripeness or close to ripeness state of your bulbs. If this isn't the case then it's possible that you might have an onion disease ravaging in your garden.

If you're particularly curious and want to see what happens when you let onions sit in the ground too long, you shouldn't because letting the onions sit in the ground after more than 80% of the top is dry leads to them rotting in the ground or the storage if you don't harvest then within the next two weeks.

However, if you started your onion from onion sets rather than the seeds or the onion bottom then they will start to flower, a process known as bolting. These onions are unsuited for consumption as their bulb core decays and results in a thickened stem unless you are collecting onion seeds.