In this tutorial you shall learn how to grow onion from your kitchen scraps. Regrowing onion from scraps is an absolutely fulfilling exercise. Onions are among many other foods that can be grown from scraps. More than likely, once you start this practise it will stick. You are never going to feel at ease throwing away any onion bottoms again unless you really must.
Growing onion bottoms which is essentially growing onion (Allium cepa L.) from another onion is super simple to do. I am aware that there are a number of approaches different people use to do this. What I am sharing here is a method I started off with and it has been my way of doing things since.
So how do you grow onions from your kitchen scraps? As implied, you first must have the onion bottom scraps to begin with. This means this would, the first time around, come from your store bought onions that you cut off when doing recipes.
This method is applicable on quite a variety of onion types be it red or brown onion bulbs. In this tutorial, I will be using a single onion bottom to demonstrate how you go about growing the onion. You are free to use as many scraps as you wish keeping in mind, as you shall see, that a single scrap can yield 3 or 4 onions regrows!
Step 1 – Get your onion & cut bottom off
The first thing is of course to get your onion. As mentioned, most onion bulbs can be regrown using this method. To perpetuate a good quality onion, ensure you get a good, healthy looking onion. In this tutorial I used red onion. However, feel welcome to use any onion type.
Since you are planning a regrow, as you cut off the scrap which you are going to regrow, make sure to leave the scrap with a bit more flesh. Proceed to use the rest of the onion in your cooking.
Also learn how to grow other vegetables from scraps such as Chinese cabbage, potatoes, regular onions and green onions a.k.a. spring onions.
Step 2 – Insert suspenders (optional)
Here I used simple toothpicks as suspenders for the onion scrap in preparation of the next step. I only need three pierced around the scrap onion to make this work. As you drive the toothpicks through the sides of the scrap, it is important to ensure that you do not pierce the “heart” or centre of the scrap. This is where the regrow will come from. Once pierced it will be compromised. This step is however optional. I prefer to do this to allow easy sprouting of roots at the bottom of the onion scrap as it is suspended.
Step 4 – Suspend the onion scrap over water
Take the bottom scrap and suspend it over water. You may use a small shallow container to achieve this. What is key is to ensure that the bottom of the scrap onion is always in contact with the water. This may mean water top-ups on a regular basis to guarantee this necessary contact. If you skipped optional step 2 above, you may need an even shallower container such that your onion bottom directly sits in water.
After some 3 to 4 days, the onion rings will start to gradually separate as shown here. This is normal. The rings must necessarily do this. It is the centre of the scrap onion that will regrow and that we are most concerned about. As this happens, if using the suspenders in step 2, keep an eye to make sure they remain secure and the onion suspended and in contact with water. As mentioned, avoid driving the toothpicks too deep and in a direct manner so as to damage the centre of the scrap onion.
Step 5 – Onion regrow visibly emerges
A few more days down the line will now reveal the regrowing onion out of the old onion. This is exciting. The question has been asked, how many onions grow from one onion? At this stage, the answer is apparent. More than one onion can regrow from one onion. In this case, I had two onions growing from one onion. It can also be three and in some cases even four onions regrowing from a single onion bottom. The size of the original onions seems to play a part here.
As you can see here, as regrow of the actual onion takes places, the roots would have also extended their tentacles right below in the water. It is the roots that power the regrow utilising just water. The rest of the food (energy) to regrow comes from the dying scrap itself as shown by the separated rings.
Step 6 – Planting the sprouted onion
Now that we have our onion sprouting from its mother onion, it’s time to take things to the soil. Using a sharp knife separate the conjoined regrows (or whatever number you may have in your case). This split will do no harm to the separated sprouts as the well developed roots will drive continued life in the soil. In this case I used a bucket of 23cm (9in) across and 17cm (6.7in) deep. I filled it with ordinary garden soil mixed with some compost.
Dig two holes into the soil in the bucket and insert the sprouts. Ensure that the holes are deep and wide enough to accommodate the rather lengthy roots that have developed. We ought to treat the roots with care as they present the only chance for the sprouts to make it in this brand new grow environment.
Cover the now planted onions with soil and water. At this point, the idea of onion scraps or bottoms is dying as we now have two legitimate onions taking root in the soil. New independent onions are on their way to full life!
Step 7 – One week later
About a week later of so, this is how things look. Taking care to water every other day, things are looking up. As you may have noticed, I now have a total of four onions growing. Making use of the still available space in the bucket I added two more onions from brown onions scraps also from my kitchen. You may also do this if your pot still has room for more.
Step 8 – Several weeks later
After a few more weeks, I now have fully mature onion plants. In the last few weeks I have been enjoying some pickings for my recipes. I removed from time to time some leaves from the onions for use in my kitchen. I also must say I lost one of the onions out of the four, I reached this stage with only three. This may happen despite your watering and care general care efforts. This is what it is also helpful to have a number of them growing at the same time.
Shown above is some detail about the size of the still growing onions. If I chopped off the leaves, leaving the rest in the soil, the onions would sprout again and again for the foreseeable future.
Conclusion
As I have hopefully convincingly demonstrated, growing onion from kitchen scraps or bottoms is plain easy. The best part is that a single onion gives you more that one onion in most cases. This means if you grow your next 10 scraps this way you may end up with at least 20 vibrant onion crops in your garden or pot! This should guarantee a good supply of fresh onion for a long time to come.
Using this method, there is absolutely no reason, except for the fun of it, one should spend any more money on onions. Growing them in pots also ensures that even where space is limited you can still enjoy the benefits of growing onion from discarded onion bottoms.
Summary on how to grow Onion Bottoms from Kitchen scraps
Here is a to-the-point summary of how to grow onion bottoms from kitchen scraps. Refer to my step-by-step tutorial with pictures for detail.
- Get a fully mature onion and cut off the bottom part. Use rest of onion in your dishes 🙂
- Pierce three sides of the cut off scrap with toothpicks as suspenders.
- Get a small container and suspend the scrap on it over water. The bottom part should sit and make contact with water submerged.
- After few days the middle of the onion scrap will start two sprout new life.
- Take a container filled with nutrient rich soil and plant the sprouted onion scraps.
- Within a week the sprouts will transform to fully fledged onion leaves.
- After several weeks, the scrap will form a new onion bulb which can be harvested.
Become a greens guru!
