I love green onions, but sometimes when I buy them, they go bad before I get around to using them. I’ve found regrowing green onions from scraps is one of the best ways to have fresh green onions year-round, any time I want them.

In this article I’ll show you two ways that I regrew green onions in water. While I’m sure you can regrow green onions in soil, I’m a big fan of growing vegetables hydroponically. Because of that, when I decided to regrow green onions from scraps, I explored ways to do it without soil.

Here’s my experience with regrowing green onions.

Why Not Just Grow Green Onions from Seed?

regrowing green onions in mason jars.

In general, I’m a big fan of growing vegetables from seed. Generally speaking, growing from seed is the most economical way to go about growing anything. It’s also incredibly rewarding to start with a tiny seed and end up with food that feeds you and your family.

However, growing green onions from seeds takes quite a while. Also at least in my limited experience, initially the green onions you grow from seed are super scrawny.

On top of that, you can purchase green onions from the grocery store pretty inexpensively, and you can regrow them amazingly fast. It’s super easy to do. When you consider the low cost of purchasing green onions, and how quick and easy it is to regrow them, in my opinion, it just makes sense to regrow green onions from scraps instead of starting them from seed.

Select a System for Regrowing Green Onions

This article includes affiliate links.

The good news is, there are systems on the market that make it super easy to regrow green onions. Here are the 3 that I recommend, all available on Amazon.

  • The Hamama Home Green Onion Kit is the best option if you use a lot of green onions.
  • This green onion “farm” that works with mason jars is a great way to regrow several green onions at a time, but has a smaller capacity than the Hamama kit.
  • These mason jar lid inserts that are compatible with AeroGarden sponges are great if you want to be able to use them for a variety of reasons, one of which is regrowing green onions. You can also use them to grow other types of vegetables such as lettuce and tomatoes.

Any of the above options work for regrowing green onions, so you can feel confident in purchasing any of them. In this article, I’ll demonstrate the growing using the second and third option, since I don’t use enough green onions to make the Hamama system worthwhile.

Trim off all but 2″ of the Green Onions

cut green onions to about 2" in length before regrowing.

When regrowing green onions, you can start off by first off, using the green onion tops. Obviously, there is no reason to toss the tops! Put them in salads, or use them as a garnish in soup, chili, or any other dish that you want to add a pop of flavor and color to.

Just be sure to leave a couple of inches at the bottom of the green onions.

Place the Green onions in the Lid and Place in Water

I used two types of mason jar lids for growing the green onions. The first lid on the left, has enough holes to hold nine green onions. The second lid has just one opening, that accommodates a single AeroGarden grow basket. You can get both of those types of lids on Amazon.

Note that while you can use an AeroGarden sponge with the second opening, I used the grow basket without the sponge.

It looks like the green onion piece on the right is much smaller, but looks are deceiving. Due to the type of lid, the green onion went much lower in the jar compared to the ones in the other lid.

In my case, I had one green onion that was so fat it wouldn’t fit into the holds in the lid on the left, so I used the AeroGarden compatible lid for that one.

Some of the green onions were so thin that they fell through the small holes on the other lid. To overcome that problem, I put a few green onions into a single hold to keep them from falling through.

Adding Nutrients to Water

Nutrients are optional, but if you want to regrow your green onions multiple times, I recommend using nutrients. I personally used AeroGarden liquid nutrients (Amazon). I put one 2 ml capful (from the small AeroGarden nutrient bottles) into 5 cups of water, and divided the water between the two pint-sized mason jars.

Blocking out Light

I cut off the “straight” part of the sock and used that to put over the jars.
cover the jars you're using to regrow green onions to block out light. This keeps algae from growing.

To avoid algae growth, I used cheap black socks to cover the jars. You can use any old socks you have. I picked up a cheap package of black crew socks, and cut off one end of each sock and used that to slide over the jars.

Watch the Green Onions Grow Like Crazy!

The amazing thing about regrowing green onions is that they grow super fast! In the image above, you can see how much they had grown in just a week!

You can see that the green onions on the left appear to be growing much faster than the one on the right. That is true to some degree, but looks are a bit deceiving. First, there were many green onions on the left, and some were growing faster and others not so fast.

I only planted one green onion on the right, and it was indeed a slow starter. Also, you can see that the one on the right sits much lower into the jar than the ones on the left.

Harvest and Enjoy Your Green Onions

regrow green onions in mason jars

By the 11th day, the green onions growing in the lid on the left ranged in height from 4 1/2″ to a whopping 13″ in height. The green onion on the right was about 7″ in height. It was also a bit thicker and sturdier. The bottom line is that both types of lids worked well for this experiment.

At this point, I began harvesting the green onions on a consistent basis. I snipped off a few inches each time I used them, and the green onions continued to grow back.

when you regrow green onions in water, the roots will grow down into the water.
Green onion roots growing in water

After about a month or so of doing this, they didn’t grow back as well. This was due to neglect on my part. I didn’t refill the water, and while there was enough water in the jars, the nutrients had likely been depleted.

If you want to keep the green onions regrowing for a prolonged period of time, I recommend changing out the water every couple of weeks. But even if you neglect it like I did, it’s still well worth regrowing green onions.

Here are the resources I recommend for regrowing green onions, all available on Amazon:

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