How To Grow Onions Using An Egg Carton

When you have some old onions, onion offcuts, or want to plant your onions, you may be tempted to grow them using egg cartons. The process can look complicated if you have only seen other people do it, with their onions in various growth states. Growing onions in egg cartons can be tricky if you are unsure of the process and how much attention you should give to them.

grow onion from egg carton

To grow onions in egg cartons, you will have to layer the egg cartons with water in the bottom carton for the roots to grow in. The onions will soon start creating shallots. In 15 days, the roots will be strong enough that you can harvest the shallots or plant the onion in your garden to grow more onions.

There are a lot of tricks you will have to know about growing onions, with some of the most surprising ones coming from the different materials that egg cartons are made from. Knowing how to grow onions in plastic egg cartons is vastly different than growing them in paper egg cartons. Even then, there are small changes that need to be made for the onions to grow.

These are the things you need to know about growing onions and the shallots that come with them!

How long does it take to grow onions?

There are different stages to all onion growth, with many of them being useful for cooking in some way or another. Many people that grow onions have them in different states, allowing either the onion or the shallots to grow exponentially.

For the growth of shallots, onions only need to be left in the water to grow, and they will start appearing after only a few days. These shallots can be harvested and used for the first time after 13 days, growing back to full length after that almost once every week. All you will need to do is provide fresh, clean water for the onions to grow in.

If you plan to grow your onions to get more onions, the process will take a bit longer, with varying results depending on your garden soil. Onions will only appear after 4 months of growth, and the onion has to be planted in soil to get proper nutrients. These plants make good additions to your garden, yield several onions, and can be replanted if harvested properly.

What will you need to grow onions in egg cartons?

To grow the first onions, you will need to have a small list of things ready, with several of them being found anywhere in your house. These are the basic items that all onion growers will come to love and use throughout their onion growing lives.

These are the six things you will need to grow onions from nothing but older onions, usually already showing some growth of roots!

  • Cartons: The most important part of the process is to have several egg cartons that you want to use for the growth. You will need at least enough cartons to make two layers of cartons. If you have plastic cartons, you can cut them in half to use them. With paper cartons, the process requires at least two of the same size. You will be layering these cartons on top of each other, with small holes cut at the bottom of each egg space, while paper cartons need to be filled with water.
  • Layers: The most important part of using egg cartons is the layers that you use to grow the onion. There have to be two layers of egg cartons, with the top carton holding the onion while the bottom layer holds the water. Plastic egg cartons should have small holes for the roots to grow through, while paper egg cartons will have an added layer of plastic to assist in holding the water.
  • Onions: This might seem obvious, but many people forget about the onions’ most important part. While you can use fresh onions, they will usually take a bit longer to grow, especially if they come from the freezer. Leave the onions somewhere mildly sunny for at least one day, then place them in the egg carton, making sure that the bottom quarter is submerged in water.
  • Water: You will have to start the growing process with water, which should be obvious. However, you will have to replace the water regularly. Several things will cause the water level to sink bbelow-recommendedlevels, and with age, the water will also lose most of its nutrient value. Replaced the water entirely every second day should keep the onions growing happily.
  • Spacer: This is only meant for plastic egg cartons. The most common tools used as space between the egg cartons are simple chopsticks. This ensures that the roots have space to grow and that the onion is not submerged too deeply in the water. This little bit of extra space will allow the onion to grow comfortably.
  • Plastic: Used only in paper cartons, the bottom layer of the carton has to be covered by a layer of plastic or glad wrap. This is to ensure that the top layer of cartons absorbs all the water and that nothing is leaking all over the place. This facilitates rapid growth in the onion and creates an environment where you only need to add water every few days to make sure nothing is drying out.

How many times can you have them grow like this?

You may notice that you can cut the shallots off and leave the plant to grow more in a few days. This is one of the big reasons people like growing their onions in egg cartons. You may also wonder just how many times you can repeat this before the plant might die or stop growing back.

You can do this in an almost infinite amount of time. With the shallots always growing back, the roots will start growing too long after a while. When your onion roots are starting to grow too long, you simply move the onion into its bottle of water, with no soil in sight. Doing so will have your onion continue to grow healthy shallots for a lot longer.

However, it is important to remember that growing onions in the ground can cause the shallots to grow a lot larger, so you need to grow the onion in water for shallots and then move it to the soil to grow more onions. You can repeat this process for an infinite amount of time.

What should you keep an eye on?

There are still things that you will need to keep an eye on when you are growing your onions in this way. The dangers of not paying enough attention or simply letting it grow wild without care can cause damage to the plant down the line. Some of the best early growers make the mistake of not paying enough attention and having onions that do not grow properly.

Water discoloration

This is the thing you will need to pay the most attention to in the early stages of growing your new onion plant. As the onion starts to grow, it will release unwanted toxins and nutrients into the water it is growing in. Usually causing the water to start turning a slightly brown, almost yellow color.

Simply replacing the water will help to stop this from becoming a problem. However, there are things you need to know about replacing the water. If you are not using egg cartons and have moved the onion to a larger bottle of water, it is recommended that you only replace half the water each time. This is because of the microcosm of microbes that have been created in the water, helping the roots grow safely.


While scallops can help to drive away from some bugs because of their strong smell, other bugs will love the smell of the plant as it continues to grow. You might not always see the bugs that can damage your fledgling onion plant, which is why you should inspect the leaves regularly.

Bugs that eat the scallop leaves will leave small traces of discoloration wherever they go. There are a few things you can do to get rid of them. Usually, removing the leaves is the easiest option, and moving the plant to a new growing location where the bugs are least likely to get to them. This is also why it is important to wash the leaves of your plants before even attempting to eat them.


Growing onions in egg cartons is a simple process of using the right tools, checking on the water levels, and trimming the scallops as needed. If you want to start your garden, this is usually the place to start, as onions are some of the hardiest plants in nature.

Just be sure you don’t mistake them for weeds once they start popping up all over your garden!

Did you find this post useful? Would you like to get back to it later? Save THIS PIN below to your gardening and vegetable garden on Pinterest! Thanks 🙂

How To Grow Onions Using An Egg Carton

One Comment on “How To Grow Onions Using An Egg Carton”

  1. Greetings from Ghana.
    Infact your post is very useful and I’m going to try right now .
    Thanks very much.
    But didn’t figure out the last one very well.
    But thanks anyway.

Leave a Reply

Your email address will not be published. Required fields are marked *