How to store onion sets?

It’s not too late to plant onions


Q: I would like to plants some onions. Can you tell me which kind do best in Redding? Is it too late to plant onions?

A: To answer your second questions first, it is not too late to plant onions if you plant them from sets. It is best to plant onions in September as you will get larger onions at harvest time but you should still get a harvest of medium sized onions if you plant now. Sets are tiny onion bulbs, grown from seed and forced into dormancy at an immature stage. You can buy these from any local nursery. These are the fastest way to get onions started.

The onion varieties that do best here in Northern California are the intermediate-day type. Onions are day length dependent plants, meaning that most onions start to grow bulbs as days lengthen. The lengthening days of late spring trigger the onion plant to start transitioning from growing leaves and roots to the business of forming bulbs. The types of onions that successfully grown in northern states, with their extra daylight hours, are different from the onions grown in the south.

Most seed packets and catalog descriptions should reveal which varieties are intended for short-day regions (those that begin to form bulbs when day length is only 10 to 12 hours), intermediate-day regions (12 to 14 hours), or long-day regions (14 to 16 hours). There are a few onions considered day-neutral; this type starts to set bulbs after a certain number of growing days. These varieties can be grown anywhere.

You may want to order your onion sets from a catalog or buy them at one of our local nurseries rather than a big box store as most garden centers label their bins of sets by color (white, yellow, or red) instead of by cultivar. If buying from a bin, resist picking out the largest sets from the bin as these can go to seed quickly instead of forming a large onion bulb. Sets that are one half inch in diameter — about the size of a dime — are the best buy.

To plant onions, place the sets in a shallow furrow and cover with just enough soil to leave their pointed tips at the soil surface. The spacing between onions should eventually be about 6 inches, depending on the mature size of the variety, but you can place the sets closer together initially and then thin later for use as green onions.

You may also see onions available in bundles of bareroot onion transplants or you can grow your own transplants by starting onions from seed in the greenhouse and setting the seedlings out in the garden in spring. To plant in the garden, dig a trench for the seedlings and place them slightly deeper than they were in the flat. As with sets, seedlings can be planted closer than their ultimate spacing of 4 to 6 inches, with the extras harvested as green onions.

Onions can also be grown from seed but they will not produce the biggest bulbs. Onions benefit from the head start they get from sets or transplants. It gets too hot here in the late spring for onions started from seed to fully grow into full size onion bulbs. But bunching onions or scallions are quicker to mature, and they can be seeded directly into the garden. Start with fresh seeds, or seeds no more than a year old, because onion seeds lose viability quickly in storage.

The Shasta Master Gardeners Program can be reached by phone at 242-2219 or email [email protected] The gardener office is staffed by volunteers trained by the University of California to answer gardeners’ questions using information based on scientific research.

Growing Onions

As with most vegetables, you can start onions from seed in the garden. But many onions have relatively long growing seasons and onion seeds don’t germinate quickly, so it’s often better to start the crop another way. You can set out transplants, or you can plant “sets” which are simply half-grown onions.

Where Sets Come From

Many sets are grown from seed on big farms near Chicago. The onion seeds are planted very thickly. Super-crowding of the plants makes the competition for water and fertilizer fairly stiff, so the plants never get very big and the resulting bulbs are quite small.

The small onions are harvested in the late summer or fall and dried for a month or more to rid them of moisture that could cause rot. Then the sets are stored until gardeners need them the following spring.

It’s said that Chicago got its name from onions. Indians, who once lived nearby, called the place “Shikako” which means “Skunk Place” after the strong smell of wild garlic, onions, and leeks that once flourished there.

Buying Sets

In the North you’ll find the first onion sets of the year at garden centers when there’s still snow on the ground.

Using sets is probably the most popular, convenient, and dependable way to get onions started. They’re very easy to plant, and you can harvest your first eating onions sooner than if you started from seeds.

Stores usually sell only a few varieties of sets, such as long-keeping white and yellow varieties and a red type or two. You can also grow sets yourself during one season for use the next year.

Sets are sold by the pound or by the scoop; each set is one onion. When you buy onion sets, watch the size. Sets that are smaller than 1/2 inch in diameter take longer to grow, but they’ll still produce. Sets larger than 3/4 inch in diameter are very apt to “bolt” or grow seed pods in a hurry after you plant them. If you let them grow seed pods (a pod looks like a miniature version of the domes on the towers of the Kremlin in Moscow), the plants put energy into the seeds and not into the bulb. The bulbs will be small, tough and won’t keep, so pick the pods or seed stalks off as soon as you see them.

The most dependable sets are the size of marbles — 1/2 to 3/4 inch in diameter — and are quite firm.

Growing Your Own Sets

To save some money and have a little onion fun, you may want to grow your own sets. Here’s how to do it: In July in the North, or August farther south, create a small section of your garden to plant a good storage onion such as ‘Yellow Globe’. Sow the seeds about 1/4 inch apart in one-foot-wide rows. Give the plants some fertilizer and just let them grow without thinning them at all.

Shortly before the first frost, bend the tops over. Wait a week or so and then dig the small bulbs out of the ground. After curing them for a few weeks, store them in mesh bags in a very cool (40° F) dry, dark place. The following spring you’ll have plenty of sets on hand.

Most southern gardeners don’t bother with growing sets because they have a pretty long season and don’t always need the head start that sets give. If you like to experiment, here is one method that works pretty well in the South; select a short-day onion seed variety that’s a good keeper and in early March sow it thickly in a wide row and leave the onions to grow. As they’ll be very crowded, the bulbs won’t get oversized. Harvest the bulbs when the tops wither from the hot summer sun. Dry them in the sun for a day or so and store them in mesh bags in a very cool, dry place. In the fall you can set them out in the garden again. They’ll put on a little root growth before it gets cold and when the weather warms up in the spring, they’ll pop back to life giving you very early onions. Of course in the deep South, where the winters are quite often mild, you can plant sets in the fall and harvest onions throughout the winter.

Buying Transplants

The best way to start big-bulb, European-type onions is from transplants. These are thin, young onion seedlings, and the optimum planting size is when they’re just the size of a pencil. You can send away to seed or plant companies for bunches of transplants, or you can sometimes buy them at your local nursery. To get mail-order transplants, order the varieties you want sometime during the winter from companies in southern states; they’ll ship them to you in the spring. You have to order by the bunch (75 to 100 plants in each bunch). As with many other things, it’ll be cheaper if you order in quantity, so getting together with friends on a big order can save you a little money.

Taking Care of Mail-Order or Nursery Plants

The first thing to do when the plants arrive is to unwrap them. The onion plants develop a lot of heat when banded together, and heat encourages rot in onions. Next, put 1/2 inch of water in a shallow baking pan, and stick the roots in the water just enough to get their “toes” wet. They’ll revive quickly. Plant your onions as soon as you can after receiving them. If you can’t plant them within a few days, forget the bath. Put the unwrapped plants in plastic bags and store them in a cool, dry place until you can plant. The refrigerator is a good spot!

You can also “heel in” your transplants until you have time to plant them where they belong in the garden. Just dig a shallow trench out in the garden (or use a container), set the plants a couple of inches deep and firm the soil tightly around them. Soil in the spring is usually wet enough to keep the roots from drying out.

If any plants have a bad odor or are slimy or slick, they’re probably rotting. Separate them from the others right away and throw them out. They won’t make it in the garden.

Growing Your Own Transplants

There’s a tremendous satisfaction in growing your own plants indoors for transplanting. For one thing you have the benefit of choosing from more varieties.

Buy your seeds early enough to start your plants anywhere from 8 to 16 weeks before the last hard frost in your area. Start the seeds in a 4-to 5-inch deep flat filled with very rich, sterile, loose soil. Sterile soil is free of weed seeds and harmful disease organisms, so the onion seeds have a better chance at the start. The various potting soil and starter mixes on the market are good, but mixing in extra fertilizer before you plant is a must. One or two tablespoons of 5-10-10 fertilizer added to every gallon of potting soil works fine for onions and other vegetables.

Sprinkle the seeds into the soil and gently press them into the soil. Try to space the seeds about 1/4 inch apart, but don’t fuss about it. It’s impossible to get them spaced exactly right, and you can always thin them if they get too close. After sowing, just barely cover the seed with a little more soil or sand and tamp it down. Next, moisten the soil and cover the flat with a sheet of plastic and then some newspaper. The plastic creates a greenhouse effect retaining the moisture, and the newspaper keeps the temperature even. (Onion seeds don’t need light to germinate.) You won’t need to water again until you take off the newspaper or plastic.

Put the flats in a nice, warm spot around 65o or 70o F if possible. (Don’t worry too much about the temperature being exactly right. Onion seeds will germinate anywhere from 40° to 80o F; they simply prefer a steady 65o to 70oF.)

Don’t put the flats on a window sill before the seedlings come up. The temperature there fluctuates too much: On a sunny day it can rise to 90o F or more, but at night it can be the coldest place in the house. That’s not good for germination; onions need an even temperature.

When the seedlings sprout, remove the plastic and newspaper and put the flats by a window or under lights. They won’t need too much attention. Just make sure they get enough water, and you should add a little fertilizer from time to time — about a teaspoon in water every two weeks is good. Pour it around the edges of the flat so that the water spreads across the whole area.

In a few weeks, you’ll notice the tiny plants getting tall and spindly. That can be a problem, unless you turn it into a plus. It’s very important that your onion seedlings not fall over and get too skinny to transplant, so when they’re three inches tall, cut them back to one inch. This is your first harvest! The trimmings are delicious in dips, salads, sandwiches or as a garnish. After you cut them, the plants will naturally produce more tops. When the tops reach three inches again, mow them back to one inch. As long as the plants are indoors, cut them back whenever they grow to three inches. With short tops the plants can put more energy into developing healthy roots, and that will help them get a good start when you put them in the ground. A few weeks before planting, stop trimming them. Top growth will be important outside.

Members of the gardening set who know and like onions give top priority to onion sets in their planting plans. Unlike most other vegetables, onion sets can be planted as soon as the soil can be worked without waiting for the weather to settle. Late cold snaps or frosts will not harm them.

This means that this versatile vegetable can be enjoyed in different ways all summer long, from zippy green onions (scallions) within weeks after sets are planted, to large dry table or cooking onions later.

Onions are grown from seeds but it is the onion sets, actually small white, yellow or red bulbs that are harvested at an early stage of

development, that give the home gardener a head start and the assurance of a successful crop. They are sold by bulk weight or count or in packages of various sizes and quantities, at garden centers and supermarkets.

Here are some things one should know about onion sets to get the most out of them:

— You plant them one way to get fresh green onions for early spring salads, and another way if you want to grow the large table or cooking onions. — The larger white sets usually result in the fastest growing green onions. Often a larger white bulb will send up two or three tangy scallion stems.

— The smaller sets, ironically, produce better large table onions.

Proper planting is the key to getting the kind of onions you want, according to Harry Paarlberg, general manager of Dutch Valley Growers Inc. of suburban South Holland, a large farmers` cooperative that has been producing onion sets for more than a half century.

The initial step, Paarlberg said, is to separate the sets you buy into large and small sizes. Then, ”if you want the early green onions, plant the larger bulbs 2 to 3 inches deep, spacing them a half inch apart in rows about a foot apart. Do this as early as soil can be tilled. A continuing harvest can be had all summer if new sets are planted at regular intervals.

”For dry cooking onions, single out the smaller sets and plant them extremely shallow–just deep enough to cover the top of the sets with dirt. Space them 2 or 3 inches apart so they have room for full development.”

The white sets generally yield finer green onions, while the yellow sets tend to produce better mature dry onions. Either kind, however, will develop into either kind of onion desired, depending on their size and how they are planted.

Gardeners who purchase enough sets for successive plantings throughout the growing season needn`t be concerned about onions` keeping quality. If stored in a dry, cool place they will make quick growth when planted and given moisture, even if they have become dehydrated.

Onions provide the earliest harvest from the vegetable plot when grown from sets. If you plan to grow large quantities to store for later use, it may be more economical to grow some from seeds of appropriate varieties. These are described in seed packets and catalogues as ”good keepers.”

Seeds can be sown thinly spaced in rows, and the seedlings transplanted later with more space in other rows to mature. Begin drying off the crop early enough to complete the job before fall rains or freezes occur. Hasten the drying process by pushing over the onion tops flat with the back of a rake to stop growth after bulbs stop increasing in size.

Begin harvesting the crop when the onion tops are about half dried. Pull or dig out the onions and spread them along the row to finish drying. After tops are fully dried, clip them off or braid them to hang, then store them where the temperature remains around 40 degrees.

A colorful, free pamphlet on growing onions from sets is available on request from Dutch Valley Growers Inc., P.O. Box 304, South Holland, Ill. 60473.



Onions and shallots are planted and grown in exactly the same way. Shallots are smaller versions of onions. Shallots grow in clumps, onions produce only one bulb. Shallots tend to have a milder flavour compared to onions. The disadvantage of shallots is that their smaller size makes peeling them a longer process.


Many people think that onion sets are a relatively modern form of growing onions however our research shows that they have been cultivated for over a hundred years, see this article dated March 1911 as proof!

An onion set is simply an onion which has not been allowed to grow to its full size. The growers of onion sets plant onion seeds very close together so the resulting onions grow very small because they are so crowded. For those who haven’t grown onion sets or seeds before one question is often asked – how many onions grow from an onion set or seed? The answer is simple, one onion grows from an onion set or a seed.


Many onion sets are “heat-treated” nowadays to stop them bolting into flower. The heat treatment involves storing the onions in very warm and sterile conditions for about four months. This effectively kills a specific part of the onion preventing them from bolting.

The key advantage which an onion set has over an onion seed comes from the fact that when you plant an onion set it is at a far more advanced stage of growth compared to an onion seed. They therefore spring into active growth much more reliably and quicker. The downside of onion sets is that they are more expensive compared to seed. In addition the number of varieties of onion sets is very small compared to the huge number of varieties which are available as seed.


For more detailed instructions on how to plant and care for onions sets, see the paragraphs below.

The calendar below is set for average UK weather conditions.
Quickly adjust it to be more accurate for your town by clicking here

All dates in this site will also be adjusted. Your setting will last for six months or more and will still be set when you revisit this site.


Onion sets are normally available for sale from early March onwards. Combine this with the fact they start growing very quickly and you can see that there is almost no benefit to be gained by sowing them under cover. Also, most onions store very well so there is no real need to planting them staggered over a period of time. The best plan is to plant all your onion sets together at one time which is the second week of April 2017 (average for UK).

If you do prefer to plant your onions sets under the protection of cloches then plant them two weeks earlier than the above date. Choose a day when the soil is not waterlogged.

Onions are not particularly picky about soil conditions but they will prefer a well dug soil, preferably a few months earlier which drains well and is neither acidic nor alkaline. Having said that they grow well in most soil conditions.

They also prefer a position in full sun or at least partial sun. Onions can very quickly become prone to disease if good crop rotation is not practiced so never grow them in ground where any member of the onion family (onions, spring onions, garlic, leeks) have been grown in last two to three years.

Planting onion sets is simplicity itself. First mark out the row with a bamboo cane or string to keep the row in a straight line. Then every 10cm / 4in make a small hole in the soil with your finger and place an onion set into it. Plant rows about 30cm / 1foot apart, just enough to allow for hoeing weeds.

It’s important to plant them the correct way up with the root end onto the soil and tassel end uppermost. The picture on the right can be enlarged by clicking on it if you have any doubts. By making a little hole for each onion set rather than just forcing them into the ground you will avoid damaging the roots.

Now gather some soil around the planted onion set so that just the top tassel appears above the soil surface. Gently firm the soil down. Scatter some long-lasting fertiliser (bonemeal or blood fish and bone) around the surrounding soil and work it into the soil surface wit a trowel.

For the first few weeks birds may well be a problem for onion sets. To avoid this spread some horticultural fleece over the soil surface and secure it down with soil or stones. The fleece can be removed after a month.

If you want to grow larger onions, the solution is to start your sets off either indoors or in a greenhouse. Simply place the sets into modules filled with multi-purpose compost a few weeks earlier than normal. They will quickly develop roots and sprout shoots. Plant them outside at the same time as you would unsprouted onion sets.

Early onion sets


Onions are one of the easiest vegetables to grow and require very little attention. Their foliage is minimal so weeding will be required throughout the growing season. In dry weather they will need to be watered – lots of water occasionally rather than small amounts often is the best way to water onions and most other vegetables.

If you have average soil then an initial feed at planting with blood, fish and bone fertiliser (see above) is all that your onions will need. Do not feed with any nitrogen rich fertiliser (especially from July onwards) which would encourage thick necks and the risk of Neck Rot.

Around the third week of July stop watering your onions even if conditions become hot and dry. The reason behind this is to encourage them to ripen which will enable them to be stored for longer in the autumn and winter. If you have the time, gently tease away loose soil from the top of the onions with your fingers to allow the top and neck to receive as much sunshine as possible.


Some varieties of onions are specially bred for planting in autumn and producing a crop in June. They are commonly known as autumn planted onion sets or Japanese onions. They can be grown in most parts of the UK. You should plant these onion sets in September up to mid October and they should produce fully grown onions in June. This will give you onions a month or two before your normal onions mature.

For full information on the varieties to choose, how to plant and care for them and some tips on how grow them if you live in wetter areas, where they would normally rot, click here to go to our autumn planted onion page.


Note that the dates for harvesting given in the calendar above are approximate ones only. Growing conditions throughout the spring and summer will greatly affect when your onions are ready for harvest.

You need to look for yellowing foliage and stems which are beginning to fall over as the key indicators for ripe onions. It’s also important to choose a period of dry and preferably sunny weather for two or three days so that the harvested onions can dry out in the sun which will greatly increase their storage life.

Our own personal routine for harvesting onions is based on extending the harvest time for as long as possible. At the end of June (our area is about average for UK weather conditions) we begin to harvest onions individually for use in the next day or so. We choose the best developed ones, dig them up with a trowel and use immediately.

Late July to early August we wait until a couple of sunny days are predicted and then dig up all the remaining onions. Do not bend the foliage over in attempt to make the onions dry quicker, this will only expose them to the risk of Neck Rot. Leave them on top of the soil to dry out for a couple of days. If the weather turns damp move the onions to a shed with lots of ventilation. Then we remove the loose soil and cut off some of the top foliage but not all. The onions are stored in a cool, dry place and used as and when needed.


Onions are generally healthy vegetables but do sometimes suffer from pests and diseases and these can be very difficult to eradicate. to visit our pages devoted to onion problems. Lots of clear pictures and expert advice.


We have reviewed over 20 onion varieties widely available in the UK. for the comparison report.


How to Grow Onions

Sowing Onion Seed & Planting Sets

Onions can be planted from seed or from sets (small partly grown onion bulbs). Sets are more expensive but they tend to be more reliable in their results and also require less work – no thinning and reduced onion fly risk.

If sowing from seed then sow in drills about 2cm deep with about 1 inch between seeds. If sowing in rows then space the rows about 30cm apart.

The soil should be moist before sowing so check the soil the day before sowing and water if the soil is dry.

If planting onion sets then they can be planted around Mid to Late March (earlier if a cloche / polytunnel is used). Again space rows about 30cm apart. Sow sets around 10cm apart as they shouldn’t require any thinning. Dig a small hole for each set and place the set in neck upwards. When covered back up with soil the tip of the neck should just show through the soil surface.

Spring onions (scallion) can be sown from April and planting should be staggered every few weeks to ensure a continuous crop throughout the growing season.


Onions will grow in most climates and are frost resistant.

Soil type

Onions will grow in almost any soil from sandy loams to heavy clay. The soil should be firm. If your soil is heavy then you can introduce some organic compost or manure into the soil to help its moisture retaining properties.

Onions prefer a slightly acidic soil – PH 5.5-6.5 is a good PH for growing onions.

Planting Onion Sets

Onions will need a realtively fertile soil with a good tilth and good dranage. If you have a heavy wet soil we recommend using riased beds to avoid potential disease caused by damp conditions. Avoid using fresh manure. Onions will enjoy a warm, sunny site. Growing onions from sets is much easier than growing from seed and perfect for the beginner. Onion sets are just small, immature onions from the previous year. Plant the onions from early March till the end of April. Red onions are more likely to bolt (go to seed) and a later April planting can reduce the chance of this happening.

Once you have your bag of little golden onions you will need to pick the best ones to sow. If you do this correctly you will end up discarding almost half of the sets so bear that in mind when deciding what quantity to order.

Here are some tips to help you pick the best:

  1. 1 You don’t want any shoots, you might think you’re getting a head start but you’ll just get a very poor quality bulb.
  2. 2 Avoid any skinny looking ones.
  3. 3 Discard anything with mould or brown patches on the skin.
  4. 4 Any very big sets are more likely to run to seed.
  5. 5 Nice, tidy and round and oval bulbs will produce an excellent onion.


Push the sets about 1 cm into loose soil approx 10cm apart with 25cm between rows, leave about half of the onion showing above the soil. Birds seem to love pulling them out of the ground and scattering them round the garden. You can solve this by placing enviromesh or cloches over them for the first month which I strongly recommend. Firm the bed before planting either by standing on a timber plank of leaving the soil to settle a couple of weeks before planting. If the soil is very loose the roots don’t get a firm hold, the plant thinks it’s starving and can run to seed (Bolt). If you want to be clever and save weeding later on you can plant through a sheet of black plastic. Spread the plastic over your prepared bed, make a hole just large enough for each set and just pop them in.

When it comes to planting onion sets vs. onion seeds or seedlings, is one method really better than the other?

When should I plant onions? And what varieties are best for my area?

These onion growing questions are always at the top of the list as the spring garden planting season begins to swing into full gear. (See : 6 Spring Crops To Start Growing Now)

The Low Down On Growing Onions

To be exact, onions can actually be grown three different ways. From sets (young immature onion bulbs), from seeds, or from seedlings (transplants).

Knowing which onions grow best in your climate is a big key to success – no matter if you plant sets, seeds, or seedlings.

So, which one is the best?

Well, in reality, all three have distinct advantages and disadvantages.

And choosing the right method all boils down to knowing what types of onions you want to grow, your specific climate, and how many hours of daylight the crop will receive.

We will get back to the onion sets vs. seeds and seedlings question in a moment. But first, let’s take a look at understanding how onions grow, and how to know which variety is best suited to grow well in your climate.

How An Onion Grows

There are two important things to know about onions before selecting how you want to plant them.

Onion sets being planted in the early spring.

One is their growth cycle. The second is understanding which onion varieties are best for your climate.

First, let’s talk about an onions growth cycle.

Onions As A Biennial Crop

Onions are a biennial crop. This means they grow, mature and seed over a two year period.

During the first year, an onion grows from a tiny seed to a bulb. If planted early enough from seed, these bulbs will grow large enough to be harvested and used that year.

But if the bulb is allowed to overwinter, it will resume its growth in year two. It is in this second year that the bulb matures to complete it’s growth cycle.

During the second year of growth, the onion will flower and set seed in the bloom head.

When this happens, it sends up a “bloom” and sets seed on the head of the flower. Thus completing the two year growth cycle.

Now on to the second subject, choosing the right variety for your growing zone.

Selecting The Right Onions For Your Growing Zone

The second important fact is that onion varieties are separated into three distinct categories. All of which are based upon the climate, sunlight, and days needed to mature.

Short Day Onions

Short-day onions are mainly grown in the south and southwest. They are the “warmer” climate onions.

These yellow Granex onions are a wonderful short day onion variety.

Short days need around ten to twelve hours of average daylight to begin forming their bulbs.

Although short day onions can be grown in northern climates, the bulbs do not mature to full size.

Long Day Onions

Long day onions are mainly grown in the northern climates. These onions are planted in the spring from sets or seedlings.

Long day onions need to get between 13 and 16 hours of daylight to begin maturing.

Walla Walla onions are a big favorite among long-day onion growers.

Long day onions cannot be grown in southern areas because the daylight never extends long enough to form or mature bulbs.

Day Neutral Onions

Day-neutral onions are a bit different in that they will form bulbs no matter the hours of sunlight.

These onions can be grown anywhere except the extreme south, where it gets a bit too hot for them to mature.

Day-neutral onions need to be planted in the fall in warm climates, and early spring in the north.

Spring onions are easily grown from onion transplants or sets.

So that all leads us to onion sets vs onion seeds and seedlings. And of course, choosing which is best for you.

Here is a break down of each planting method, along with the advantages and disadvantages of planting each way.

Planting Onion Sets Vs. Onion Seeds & Seedlings – Choosing The Best Method To Plant

Growing Onion Sets

Onion sets are small onions grown from seed the previous year. Instead of being allowed to mature, they are harvested as an immature bulb. Then, they are kept dormant until the following spring and planted.

Planting onion sets in the early spring.

Once planted, they mature into full-grown onions during their second year.

The advantage with bulbs is they already have a head start on their growth. Not only can they be harvested sooner, they can also lead to harvesting larger bulbs.

But, there is a disadvantage. With onion sets, you are limited to very few varieties.

In the world of onions, there are hundreds of available varieties available. But with sets, they are usually found only in only the more common white, yellow and purple varieties.

Onion Seeds And Seedlings

The advantage of growing from seed is that you open yourself up to a wide range of varieties.

Although you can direct seed into the ground in warmer climates, onion seeds take a long time to grow and mature.

Planting seed directly can be a tedious process. And, very hard to weed as they sprout.

That means for warmer climates, they need to be sown in the fall or late winter.

For northern climates, seeds should be started indoors 10 weeks prior to moving outside to transplant.

In essence, this is the process of planting onion transplants or seedlings. And, it is a much better way to plant with seeds.

For starters, it allows the onions to get a head start. In addition, it makes weeding and bed care much easier than trying to see the tiny seeds against any weeds as they sprout.

Here is to growing your own delicious crop of onions this year!

Seed Links :

Short Day Seeds :

Long Day Seeds : Walla Walla Onion Seeds

Day Neutral Onion Seeds : Sierra Blanca Seeds

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Storing Half an Onion

To find the best way to store half a leftover onion, we gave the most popular recommendations a try, keeping samples in the refrigerator for two weeks before evaluating the results. The first sample, which was stored in water, turned brown (as did the water) and swelled noticeably. Swapping the water for oil, as some sources suggest, was also a failure; the onion became unmanageably greasy. However, those that were stored cut side down—either wrapped tightly in plastic wrap, in a zipper-lock bag, or in an airtight container—showed much more promise. The cut side dried out a little, so we cut a thin layer from the cut surface of all three samples before comparing each one, raw and cooked in a rice pilaf, to samples prepared using a freshly cut whole onion. Tasters found that when eaten raw, the older onion tasted metallic, sour, and harsh compared with the fresh onion. However, in the rice pilaf, no one could distinguish between the fresh and stored onion.

THE BOTTOM LINE: Store leftover halved onions wrapped tightly in plastic wrap or in a zipper-lock bag or airtight container in the fridge for up to two weeks. Be sure to use the stored onions only in cooked applications.

Whole dry bulb onions should be kept in a cool, dry, dark place with plenty of air movement. Lack of ventilation will reduce their storage life.

Refrigeration is only necessary when trying to extend the shelf life of sweet or mild onion varieties with high water content, but be sure to use a low humidity setting; they must be kept dry.

  • Refrigerate whole peeled onions after purchasing.
  • Store cut onions in a sealed container for up to 7 days.
  • Always keep pre-cut onions refrigerated and use before the expiration date.

How to Can, Freeze or Dehydrate

Canning is commonly called for in pickled onion recipes. Pearl, boiler, or cut onion pieces are usually hot packed into jars and processed in a boiling water canner. The USDA offers a complete guide to canning here.

Q: How do I dehydrate onions for cooking?

A: Most methods call for onions to be blanched first, then dried in a dehydrator or oven. Drying time for onions is 6-10 hours. The procedure and technique may require some trial and error until you to decide which technique works best. Remember, onions vary in water content from spring/summer to fall/winter.

Approximate Yield: 12 pounds raw = 1-1/2 pounds dry.
Storage Tip: Dried onions will reabsorb moisture and deteriorate during storage. Package in airtight containers and keep in the freezer for best results.

Q: Can I freeze onions?

A: Yes, you can freeze cut onions to use for cooking. Because the texture of an onion will deteriorate in the freezing process, it would not be suitable to use raw.

It’s really difficult to think of a life without onions: and we’re not just saying that because we’re based in Poland! Onions are used in many recipes across the world. Chances are they’re on your shopping list more weeks than not. But once you buy them, do you know how to store onions optimally?

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Even if you’re not aware of it, onions have pretty much been omnipresent. Originating from central Asia, they have been known to be used in prehistoric diets, revered by ancient Egyptians, and used as currency by Medieval Europeans.

But what’s the best method for storing onions? If you’re curious about how to store onions, or how to prolong their shelf life, then read our guide below.

How to Store Onions

Can Onions be Kept in the Pantry?

Whole onions – the best way to increase the shelf life and keep onions fresh is to store them whole. Place them in a well ventilated cool dark place: between 40-50f (4-10c). Onions will start to sprout and rot if exposed to too much moisture and light.

You can store them by tying their stalks to rope or string and hanging them. You can even put onions in plastic mesh tubing or old tights/pantyhose. Once, placed in these, tie a knot around each individual onion to allow the maximum amount of cool air to flow around each of them.

Do not keep them in a plastic bag as this is not breathable. Doing so will cause moisture to gather in the bag and speed up the rotting process. Alternatively, you can keep them in a woven basket.

Onions will last longer in climates or seasons that are cool and dry, due to the lack of moisture in the air. So, expect onions to have a shorter shelf life in the summer than they do in the winter, even when storing them optimally.

Half an onion – once cut, onions will start to decay quickly. Therefore, they’re not suitable for storing in the pantry and they should be stored in a refrigerator instead (see below).

Chopped/sliced onions – these should also be stored in a refrigerator (see below).

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Can Onions be Kept in the Refrigerator?

Whole onions – it is not at all recommended to store whole onions in the refrigerator. This is because the air inside the fridge is very moist, causing them to rot quicker. Instead, they should be stored in a dark and cool dry place to make them last the longest, such as a pantry (see above).

Half an onion – place the half an onion cut-side down and wrap it tightly in clingfilm/plastic wrap or place it in an airtight plastic storage container or plastic zipper bag. This will make sure the onion doesn’t dry out, and also prevent oxygen and additional moisture getting to it.

It is not recommended to use the half an onion raw, such as in a salad or salsa, after storing it in the fridge. They should only be used in cooked dishes.

Chopped/sliced onions – do not wrap these in clingfilm/plastic wrap as it will be difficult to create an airtight seal around the onions. Therefore, we highly recommend a plastic storage container or a plastic zipper bag.

Can Onions be Kept in the Freezer?

Whole onions – these shouldn’t be frozen as the defrosting process will cause the cell structure to break down making them mushy. This will make it difficult to slice or chop.

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Half an onion – like a whole onion, the defrosting process will mean the remaining half will be very difficult to prepare as it will be very soft after defrosting.

Chopped/sliced onions – this is perhaps the best way to store prepared onions as it increases their shelf life the longest. What’s more, it can save a lot of time during cooking as it’s possible to use the prepared onions straight out of the freezer and in the pan without defrosting them.

Store them in a plastic zipper bag or plastic storage container. When placing the prepared onions inside of these, be sure to spread them out as evenly as possible. This means that when you come to use them they’ll defrost quicker, or cook more evenly when cooking them without defrosting.

How long do onions last?

Pantry Refrigerator Freezer
Whole onions expire in… 1-6 months

(depending on climate and season)

Half an onion expires in… 6-10 days
Chopped/Sliced onions expire in… 6-10 days 6-8 months

How to Tell When Onions Have Gone Bad

Look – whole onions that have gone bad may develop dark spots on their outer layer which will begin to grow mold. Furthermore, they will also start sprouting green shoots from the top. As for half, chopped, or sliced onions, you might see mold develop on them. This looks like thin white hairs.

Feel – whole onions should be smooth and firm. If they have soft areas it means they have begun to go bad. For a half, chopped, or sliced onions, they will have gone bad if they have a slimy texture to them.

Smell – onions that are starting to rot will also start to smell bad. Whilst many people find onions already have an unpleasant smell, anything that doesn’t smell like onions, or smells even worse, means that they’ve gone bad.

Now that you know how to store onions, you might want to check out how to store other products by checking out our “How to Store…” section.

Do you store your onions differently? Are there any storage methods that surprised you? Do you regularly freeze chopped onions? Let us know in the comments.

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