All You Need To Know About Growing Onions
You grow onions at home and have some questions that need to be answered? Great!
This article is exactly for you since I answer all questions about growing onions that you could ever imagine.
Table of Contents
Time & Duration
Do onions grow year-round?
While it is possible to grow onions year-round, I still recommend you just plant them in the main season since your onions will just grow much better during spring and summer compared to growing them in autumn or winter.
Not only will you be able to grow onions in the main season much faster, but you can also expect much higher yields.
Do onions grow fast?
It can take up to 6 months to grow onions from seed to harvest.
This means that you will need lots of patience in this regard.
However, always remember that gardening is not all about speed.
It’s about loving the process and the longer it takes you to grow onions, the longer you can enjoy the ride.
How long does it take to grow onions?
While it will take beginners between 5 and 6 months to grow onions from sowing to harvest, experts can usually save up to one month since they are often more knowledgeable and can avoid mistakes right from the beginning.
Hence, if you want to grow onions at home rather quickly, you should make sure to read this article and also my grower’s guides carefully to improve your gardening know-how in general.
Do onions grow back every year?
No, onions are grown as annuals and are therefore only harvested once a year.
If you want to get multiple onion yields a year, you also have to plant onions multiple times a year.
Hence, if you search for a plant that you only have to plant one time and then enjoy the results for many years, onions are definitely not the right way to go and you should rather grow rhubarb or herbs instead.
How long do onion plants live?
Onion plants live as long as you don’t harvest them and winter frost hasn’t already arrived.
Yet, by harvesting your plants, you will remove the whole onion plant from the ground and this means that you have to dispose of the plant material afterward.
Consequently, as soon as you harvest your plants, the life of your onion plants will be over.
How long does it take until your onion plants flower?
It usually takes two years for your onion plants to flower.
Hence, if you want to save seeds from your plants, you should not harvest them in the first growing year but rather leave them in the ground.
However, by doing so, you will still miss out on the actual onion yield.
Thus, if you want to save seeds but still get decent onion yields at the same time, I recommend you harvest most plants in the first year and only leave few of them in the ground for saving seeds in the second year.
Can you grow onions in fall?
While you could grow onions in fall in theory, I still recommend you just grow them in main season in spring and summer instead of fall since your plants will just get much more sun and better overall growing conditions.
If you grow onions in fall, you will likely have much lower yields and you will also have to grow onions indoors since they will mature during winter months and will not be able to resist frost outdoors.
Can you grow onions in winter?
I also don’t recommend growing onions during winter.
Of course, if you know what you are doing and also have the patience to do so, you could grow onions indoors in winter.
However, your onions will just not grow indoors as well as outdoors since you will just not be able to provide the same natural growing conditions to your plants.
Moreover, lighting will be a serious issue and chances are that you will be pretty unsatisfied with the growth behavior as well as with the yield of your onion plants when growing them in winter.
Hence, I recommend you just grow onions in spring since it will just make your life much easier and your growing project more efficient.
Location & Climate
Will onions grow in shade?
While onions will grow in shade, they will grow much better if you provide them with a healthy mix of sun and shade.
Growing onions in completely shady environments is never a good idea since your plants will just not get sufficient sunlight to grow in a healthy manner.
Will onions grow in partial shade?
Growing onions in partial shade is perfect since your plants will get enough sun but will still be protected against excessive heat and radiation.
In turn, your onion plants will grow much better compared to just growing them in total shade or full sun.
Do onions grow best in full sun?
While many other plants grow well in full sun, you should not grow onions in full sun.
Instead, choose a spot in your garden or on your balcony where your onions get some shade so that they are not exposed to full sun all day long and don’t overheat or dry up.
Will onions tolerate frost?
While onions tolerate the cold, they don’t like frost at all and if you are not careful, your onion plants will just decay if you expose them to too low temperatures outdoors.
Therefore, make sure to wait with growing onions outdoors until you don’t expect strong winter or spring frost anymore.
Do you have to protect onions from the sun?
Yes, you should not expose onions to full sun. Instead, choose a site where they can get a healthy mix between sun and shade.
This is especially important for plants that are still quite young since the smaller your plants, the more vulnerable they are to sun exposure and the more likely it is that they get sunburned or dry up.
How much space do you need to grow onions?
You should plan one square foot of space per onion plant to make sure that your plants don’t compete for sunlight or nutrients with each other.
Of course, if you have a big garden and space is not a factor for you, you can also provide your plants with even more space.
The more space you give your plants, the better they will grow on average.
Will onions grow indoors?
While it is possible to grow onions indoors, I still don’t advise you to do so since you will not be able to provide the same natural conditions to your plants as outdoors and you may also attract certain pests inside your home.
However, if you don’t have another choice and urgently want to grow onions indoors, you can definitely do so as long as you choose a bright and sunny spot inside your four walls and also use big pots so that onion bulbs can develop in a healthy manner.
Can you grow onions without a garden or balcony?
You can also grow onions at home if you don’t have a garden or a balcony.
In such a case, you will have to grow onion plants indoors.
As mentioned earlier, this can cause certain problems and I therefore recommend you wait with growing onions until you are able to afford to live at a bigger place where you can provide better conditions to your plants.
Can you grow onions in small flats?
The smaller the place you live in is, the more difficult it will be for you to grow plants indoors since you will just not have enough space for growing those plants in decent numbers.
Consequently, if you currently live in a one-bedroom apartment and don’t have a balcony, I highly recommend you wait with growing onions until you move to a bigger place.
Can you grow onions in an aquarium?
Growing onions in aquariums is a rather exotic idea.
While it is possible to fill an empty aquarium with soil and using it as kind of a pot, it still causes problems since excess water will not be able to run off and waterlogging will occur.
In turn, chances are that the roots of your plants will start to rot sooner or later.
Can you grow onions in a terrarium?
You could also grow onions in terrariums. While this would be possible in theory, you will face the same challenges as with growing onions in aquariums.
You will often just not have the opportunity to make excess water run off properly and your plants will just not grow as well compared to a state where you just use conventional pots from the garden center.
Can you grow onions in a bucket?
Growing onions in buckets is perfectly doable.
However, before you fill your buckets with potting soil, make sure to drill small holes into the bottom of the bucket so that water can run off and waterlogging and rotten roots will not become an issue.
Can you grow onions in bags?
You can also try to grow onions in bags.
If you want to do so, make sure to use fabric instead of plastic bags since they are much stabler and water will also run off much better.
Moreover, also make sure to use big bags so that your plants get enough nutrients and onion bulbs can develop underground in a healthy manner.
Can you grow onions in hanging baskets?
Growing onions in hanging baskets is another great alternative to using conventional pots.
You will be perfectly fine by using hanging baskets to grow onions at home and you can expect pretty decent results as long as those hanging buckets are big enough.
Can you grow onions in rainy climatic zones?
Growing onions in rainy climatic zones is definitely possible.
However, it may still take you longer compared to growing onions in zones with lots of sunlight since your plants will grow slower and will therefore take longer to produce onion bulbs.
Can you grow onions in tropical climatic zones?
Most onion varieties don’t grow well in the tropics since they rather enjoy cool to medium temperatures and also don’t like excessive moisture in the air.
Hence, if you want to grow onions in the tropics, make sure to choose a local variety that is used to the heat and the extreme conditions in those regions in general.
Can you grow onions in regions with permafrost?
Growing onions in regions with permafrost is only possible if you use a greenhouse or by growing onions indoors.
Both options are not perfect. Using a heated greenhouse implies spending lots of energy and money, which not only hurts your pocket but also our environment.
Growing onions indoors also doesn’t work that well and I therefore recommend you just rely on onions from the store instead of growing them yourself if you live in one of those extremely cold climatic zones.
Do onions grow on vines?
Onions don’t grow on vines. Instead, while the plants grow above the ground, onion bulbs will develop underground.
If you have never seen onion plants before, you should definitely make sure to check out one of the videos in this article to expand your knowledge in this regard.
Do onions grow underground?
Yes, onion bulbs grow underground.
However, this doesn’t mean that the whole plant grows underground.
In fact, the plant material will grow above the ground while only the onion bulbs will grow in the soil.
What is the best orientation for growing onions?
Since onions prefer a healthy mix between sun and shade, I recommend you either grow them in west or east orientation.
You may also be able to grow onions well in south orientation.
Yet, they may get too much sunlight and this may do more harm than good to your plants.
Also avoid planting onions in north orientation since they would barely get any sunlight at all in such a case.
Can you grow onions with indirect sunlight?
Onions also grow well with indirect sunlight. For instance, instead of growing them outdoors, you can also just grow onions in greenhouses.
This will give you the opportunity to protect your onion plants from excessive radiation while still providing enough sunlight to your plants in an indirect manner.
When to grow onions from seed?
You should start growing onions in early spring.
In case it is still too cold in your region during this time outdoors, you may grow onion seedlings indoors and transplant onions outdoors later in the year.
Where do onions grow best?
Onions grow best if you grow them in half-shady environments outdoors in your garden where they will have enough space.
Avoid planting onions without sufficient space to each other so that they get enough nutrients and sunlight and can grow in a healthy manner.
Where to grow onions in pots?
If you want to grow onions in pots, the best location will be a half-shady spot on your porch since your plants will be protected from extreme outdoor conditions but will still get enough fresh air and sunlight to grow in a decent manner.
Where to grow onions indoors?
If you want to grow onions indoors, you should make sure to choose a sunny spot inside your four walls so that your onions get enough sunlight and can grow in a healthy manner to provide you with decent yields later in the year.
Can you grow onions in water?
Growing onions in pure water is almost impossible.
Yes, if you add enormous amounts of fertilizer to this water, your onion plants may grow to a certain point.
Yet, you will still not be able to get decent results and I highly recommend you just grow onions in potting soil from the store instead of trying to grow them in such an alternative way.
Can you grow onions with LED lights?
If you grow onions indoors, you may also think about using LEDs or other artificial lighting to improve the growing conditions of your plants.
While using this additional lighting may help to a certain extent, it still cannot replace decent natural lighting conditions and will also cost you lots of energy and money.
Consequently, instead of using artificial lighting for growing onions, I recommend you just grow them in a sunny spot inside your home.
Even better would be growing onions in sunrooms or outdoors.
Can you grow onions in dark rooms?
As mentioned before, growing onions in dark places is never a good idea since your plants will just lack sunlight and will therefore not grow as well.
Thus, make sure to offer your plants a sunny spot inside your home instead of growing them in dark rooms where they will most likely not prosper.
Can you reuse soil for growing onions the next year?
You can use soil for growing onions multiple times.
However, you should still make sure to add some fertilizer to the soil so that your plants will get sufficient amounts of nutrients for many growing years to come.
Do onions grow well in waterlogged soil?
No, onions don’t grow well in waterlogged soil.
Sooner or later, the roots of your plants will just start to rot and the soil will also start to smell pretty unpleasantly.
Consequently, make sure that water can always vanish properly so that waterlogging will never become an issue for your onion growth project.
Do onions grow in acidic, neutral or alkaline soil?
Onions grow best in slightly acidic or neutral soil.
In fact, the optimal soil pH for growing onions is between 6.2 and 7.
Yet, don’t be afraid of all this technical stuff.
Just get some decent potting soil from the store and you will be perfectly fine in this regard as long as you follow all the advice in my articles.
Will onions grow in sandy soil?
While you could grow onions in sandy soil, they still grow better in conventional potting soil and I therefore recommend you choose a soil mix that doesn’t contain too much sand if you want to maximize your yields.
Will onions grow in clay soil?
While you could also grow onions in clay soil, I personally don’t like it since clay soil will often be quite solid and waterlogging may therefore become an issue.
Hence, instead of using clay soil for growing onions, you should rather go for a balanced soil mix.
Will onions grow in compost?
Onions will also grow perfectly fine on compost.
Thus, if you make your own compost in your garden, you will be good to go and don’t have to rely on potting soil from the store anymore.
Do onions need a lot of water?
Compared to other garden plants, onions don’t need a lot of water.
However, please note that this also greatly depends on the region you live in.
For instance, if you live in the middle of the desert, you will need to water your plants quite often so that they don’t dry up.
However, if you live in rather moderate climatic zones, you will not have to spend lots of water on your onion growth project.
Do you have to water onion plants on a regular basis?
Whether you have to water your plants on a regular basis depends on how the weather is doing outdoors.
If it rains a lot and you grow onions outdoors in your garden, you will not have to water your plants at all since nature will do the job for you.
However, if you grow onions in pots in locations where they will not be able to get in touch with rainwater, you will have to water your plants more often.
Hence, make sure to adjust your watering schedule in line with changes in weather conditions in your region.
Should you use filtered or unfiltered water to water onions?
There is virtually no difference in the growth behavior and in the yields by changing from using filtered to unfiltered water or the other way round.
It just doesn’t matter much whether you use filtered or unfiltered water and you should just not worry about those minor issues and rather spend your time on the things that really affect the growth of your plants substantially.
When to stake onion plants?
There is no need to stake onion plants.
Onion plants stay relatively small and will therefore be resistant enough to deal with rain, wind and other adverse conditions without your intervention.
What to tie onions with?
If you really want to tie or stake your onion plants, you can just tie your plants with cords to sticks and you will do perfectly fine in this regard, even though it is not even necessary to stake onions in my humble opinion.
What to do when onion plants turn yellow?
If onion plants turn yellow, this usually happens when you either water your plants too much or too little.
In such a case, make sure to adjust your watering schedule and see if there is any progress.
If not, you may also want to fertilize your plants more often and see if the leaves of your onion plants turn green again.
How to protect onion plants against wind?
There is no need to protect onion plants against wind.
They will just be resistant enough to deal with wind on their own.
If you want to give them additional support, you can also just tie your plants with cord to sticks as mentioned earlier in this article.
How to protect onion plants against heavy rain?
There is no need to protect onion plants against rain.
Just let them grow and they will soon become strong enough to deal with rain in a completely natural manner without the need for any intervention from your side.
How to protect onions against hail?
If you grow onions in pots, you can just move those pots to protected areas when you expect hail.
If you grow them directly in your garden, you can try to protect your onion plants with some foliage cover from the garden center.
Should you pinch out onion plants?
You should not pinch onion plants, at least if you are still a beginner when it comes to growing onions since you can do more harm than good.
Instead, just let your onions grow and let nature do its work and you will be impressed by the results.
Where to pinch onion plants?
If you still want to pinch onion plants, make sure to do it outdoors so that you can avoid a mess inside your four walls and also don’t attract insects inside your home.
Can you grow onions without fertilizer?
Yes, growing onions without using fertilizer is perfectly doable as long as you provide rich soil to your plants and also give them enough space so that they don’t have to compete for nutrients with each other.
However, to really maximize your yields, you should still consider using some natural fertilizer.
Should you cover your onion plants to protect them against frost?
I personally don’t recommend you cover your plants since you will just confuse your plants due to the altered lighting conditions.
Instead, just wait with growing onions outdoors until you don’t expect frost anymore and there will just be no reason to cover your plants. Instead, you can just let them grow in a completely natural manner.
Pests & Diseases
Can you grow onions without using pesticides?
It is definitely possible to grow onions without using any pesticides.
In fact, onions are quite resistant to pests and if you provide good growing conditions to your plants, chances are that your plants will get strong and resistant enough to deal with pests on their own.
Should you use natural or chemical pesticides for growing onions?
If pest infestations are too severe, you may not have any choice other than to use pesticides.
In such a case, at least make sure to use natural pesticides instead of chemical substances to protect the soil and our environment in general.
Also your onions will be more organic and healthier if you minimize the amount of chemical substances used for your gardening project.
What are the most common onion pests?
Nematodes, eelworms and thrips are quite common garden pests when it comes to growing onions.
However, there are still many more pests you might have to deal with and it is therefore crucial that you know how to get rid of these pests in a simple but yet effective manner.
How to protect onion plants against pests?
Getting rid of garden pests is not difficult if you know what you are doing.
Are onions good plants to grow for children?
Growing onions is a pretty nice idea in case you have children at home since it is rather easy to grow onions in a decent manner and you cannot do that much wrong.
Hence, especially if you are a beginner and search for an easy entry to the world of gardening also for your kids, growing onions definitely makes sense in this regard.
Are onions good plants for a school project?
While growing onions is not difficult, it can still take up to 6 months to grow them from seed to harvest and I therefore recommend you grow different plants that will take you much shorter to grow.
Hence, instead of growing onions as a school project, I recommend growing carrots or lettuce instead.
Is growing onions difficult?
As mentioned before, growing onions is not difficult at all.
In fact, onions are among the easiest plants to grow at home and even if you are still a beginner in gardening, you can definitely expect decent results as long as you follow all the advice in this article.
What color do ripe onions have?
Since onions will grow underground, you will not be able to rely on the color of your onions to determine when they are ready to harvest.
Instead, you should just wait until harvesting time arrives and then remove a little bit of soil from the top of the bulbs you should see under your plants.
If those bulbs have a decent diameter as you know it from the store, you will be fine harvesting your plants.
Can you save seeds from onion plants?
You can also save onion seeds and use them for future growing projects.
However, please note that onions usually don’t produce flowers in the first growing year but that you rather have to wait two years until this happens.
Hence, if you want to focus on maximizing your onion yields instead of saving seeds, I recommend you just get some onion seeds from the store instead of dealing with saving seeds from your own onion plants.
Can onions get overripe?
Yes, onions can get overripe and will finally rot if you don’t harvest them in time.
Thus, make sure to remove them from the ground once the time has come to harvest the fruits of your labor.
What parts of an onion plant can you eat?
You can both eat the onion plant as well as the onion bulb (commonly known as onions).
If you don’t like the taste of the plant material, just dispose of it and only use onion bulbs which you can harvest underground.
Is growing onions expensive?
No, growing onions is fairly cheap. If you have a garden, you even don’t have to get any pots but you can just plant onions right in the ground at virtually zero cost.
Even if you have to get some equipment, gardening is still not the most expensive hobby and almost everyone will be able to grow plants at home from a financial perspective.
Is growing onions fun?
In my opinion, growing onions and other plants at home is quite interesting and I personally really love to see the progress of my plants every day.
Gardening also helps me relax in stressful periods of my life and has become a quite nice hobby for me.
Do onions grow on trees?
No, onions grow on plants, not on trees.
While the plant material grows above the ground, onion bulbs will develop underground and you will therefore barely be able to see them before harvesting your plants.
Do onions grow from flowers?
No, onions don’t grow from flowers.
In fact, there is no need for your onion plants to flower to form bulbs and you don’t have to worry about it at all, at least if you don’t want to save seeds from your plants.
How many onion plants should you grow per pot?
If you grow onions in small pots, I recommend you only grow one onion plant per pot.
However, if you use big pots, you may be able to grow multiple onion plants in this pot as long as your plants have enough space to grow in a healthy manner.
Which animals feed on onion plants?
Squirrels, rabbits, mice and birds are just a few of the animals you will have to keep away from your onion plants if you want to grow them outdoors.
Hence, make sure to install a fence around your garden plants to protect them from those hungry friends.
Will your pets eat your onion plants?
Also your pets may try to feed on your onion plants. This will neither be good for your plants nor may it be good for your pets.
Thus, make sure to take measures to separate your pets and your onion plants to avoid any issues in this regard.
Are onion plants toxic for pets?
Onion plants can also be toxic for certain pets.
Hence, to assure the health of your pets and your plants, make sure that your pets never feed on your onion plants.
Why onions grow small?
If onions grow small, this usually means that you haven’t provided good growing conditions.
For future growing projects, make sure to offer more space to your plants and you may also add some fertilizer in such a case so that your plants get more nutrients.
Also make sure that your plants get enough sunlight so that you can expect higher yields in the future.
What to grow with onions?
There are many plants you could grow with onions. I listed the best ones in my onion companion plants article.
Can you grow onions from onions?
Growing onions from onions is possible.
However, this may be rather inefficient since you often only get one onion from each plant.
Instead, I recommend you grow onions from seed so that you don’t waste food.
Can you grow onions from onion slices?
No, you cannot grow onions from onion slices since you would just destroy the growing potential of your plant.
Instead, either grow onions from whole onions or use onion seeds from your garden center.
Can you grow onions without seeds?
Instead of growing onions from seed, you could also just grow them from onions from the store.
Alternatively, you could also just get some onion seedlings from the garden center if you want to grow onions even faster.
Do you have to pollinate onion plants?
No, you don’t have to pollinate onion plants by hand. Instead, just let nature do its work and you will be perfectly fine in this regard.
It is not even necessary for your onion plants to flower for getting onion bulbs and you should therefore not worry at all in this regard.
How to grow big onions?
If you want to maximize the yields of your onion plants, you also have to optimize growing conditions.
This means providing an optimal site for your onions and also to providing sufficient space and nutrients to your plants.
Furthermore, you should also optimize your watering schedule to improve growing conditions even further.
By doing all of that, you can be relatively sure to get decent onion yields.
Can you grow onions commercially?
While growing onions commercially is possible in theory, this market is quite fierce and you will therefore never be able to compete in it.
Consequently, I suggest you just grow onions as a hobby instead of building a real business around it.
Can you grow onions from fresh seeds?
Yes, you can grow onions fresh seeds.
Alternatively, you can also rely on seeds from the garden center if you don’t want to do the work for saving onion seeds.
Can you grow onions from dried seeds?
If you save onion seeds but you don’t want to use them right away, you can also dry them in dark and dry places inside your home and use them for future growing projects.
Can you grow onions from rotten fruits?
You can also use onions that are no longer suitable for consumption for growing purposes.
However, make sure that there is no mold on them.
If this is the case, just dispose of those onions right away and don’t use them for growing purposes anymore.
Can you grow onions from cuttings?
Growing onions from cuttings may be possible in theory, yet it is almost impossible in practice.
Hence, especially if you are still a beginner, you should rather grow onions from seeds instead since it is just much easier.
Should you use an onion growing kit to grow onions?
You could also use an onion growing kit to grow onions.
Yet, in my opinion, this would just be a waste of money and you should rather just get some onion seeds and some potting soil and you will be good to go.
Do onions grow in the wild?
Yes, onions also grow in the wild.
Yet, they often look quite different from what we know from the store.
Should you talk to your onion plants?
There is no proof that talking to your plants will improve their growth behavior or their yields.
Hence, instead of talking to your onion plants, I suggest you just use your time for more important things instead.
Should you plant onions at half moon or full moon?
It doesn’t matter whether you grow onions at half moon or full moon.
Instead, just do what’s good for your schedule and don’t worry about those moon phases.
I hope you have found the answer to the question you were looking for.
If you want to learn even more about growing onions, make sure to also check out my onion grower’s guide where I show you how to grow onions from seed to harvest.
Own research and experience
About the Author
My name is Andreas and I’m really passionate about our environment and also about growing plants. In fact, I have grown several different plants over many years. I love to see my plants grow and also always try new things to improve my overall conditions at home.
In my blog posts, I want to share my experiences with you so that you can become successful in growing various different plants and improving your home as well, even though you might still be a beginner right now.