How to Grow Spring Onions In Water

Want to know how to grow spring onions in water? Then follow these easy instructions in this quick ‘How to’ post. This could be fun for the kids as well so why not get them involved?

Growing spring onion (Allium fistulosumplant cuttings in water is easy, and best of all it will save you money on any further ‘spring onion’ costs in the long run. We all know how important that can be these days. 

All you need to get going is a clean see-through jar (so you can monitor growth), some spring onion trimmings  (this is the bulbous white root + 1in (25mm) of the green leaf) and some clean tap water.

How to grow spring onions in water

How to Grow Spring Onions in Water in 4 Easy Steps

Preparing Spring Onions For Growing In Water

Ensure though that when you prepare spring onions for growing in the water you allow a little of the green leaf to remain, the rest of the ‘green’ you can cut and eat in salads or sprinkle on your ‘pizza’. Also, try and get some of the bulbous onion with some roots already showing, this will help start you off.

Start by chopping the spring onion bulbs to around 30-40 cm (1¼ – 1½) from the roots, then place these cut bulbs (several pieces) in your jar or small pot in a sunny spot on a kitchen sill or similarly warm sunny area. Always try to avoid placing them in ‘direct’ sunlight though as ‘algae’ may grow in the water, this will cause you some problems. 

To be safe the water should always be clear and not cloudy this will give you the best opportunity for your spring onions to grow.

If you leave them now, you will be surprised how your spring onions will sprout very quickly, and you should see in just a few days or less than a week, the roots starting to grow and those green leaves also starting to shoot up.

Please note, as we advised, change as needed, but change the contents completely not in part, usually around every 2-3 days but do not overwater, just keep an eye on the water in the jar.

How to Grow Spring Onions In Water: One of The Easiest Vegetables to Grow in Water For an Endless Supply is Spring Onions

Here We Go Again

If you give your spring onions a chance to regrow, you can snip them as before at the base as you need them and start the process all over again. If you have a good supply and no need for them right away why not try freezing your spring onions?


How Long Does it Take to Grow Spring Onions in Water?

It takes about 7-14 days to grow complete spring onions in water. You should see new growth within a few days of placing the onion in water, and the onions should be ready to harvest within 2 weeks.

Do Spring Onions Need Sunlight to Grow?

Yes, spring onions need sunlight to grow. They should be placed in a sunny spot if you are growing them in soil. If you are growing them in water, they should also be placed in a sunny spot to encourage new growth.

Do Spring Onions Need Fertiliser When Grown in Water? 

Yes, spring onions grown in water can benefit from a small amount of fertilizer. You can add a few drops of liquid fertilizer to the water every few weeks to provide the onions with the necessary nutrients to grow.

Can Spring Onions Be Grown in Hydroponics?

Yes, spring onions can be grown in hydroponics. Hydroponics is a method of growing plants without soil, using a nutrient-rich water solution instead. This method can be more efficient than traditional soil-based gardening and can produce higher yields of vegetables, including spring onions.


Growing spring onions in water is one great way to save money on your food bill, every little helps. But it’s not all plain sailing. We saw with this post, a few simple steps and you will discover what you need to know in order to successfully grow spring onions without soil.

You found out the best position to place your pots on your windowsill (or wherever you plan to grow your onions) as well as some tips and tricks to help get the most out of this method. In the meantime, good luck and happy onion growing.

If this post has helped you in any way, please share it with your family and garden-loving friends or anybody looking to know How to Grow Spring Onions in Water.

Finally, you can always pop over to our FAQ page. It’s full of information on a whole host of gardening tips and tricks, queries and gardening jargon you may need to know about a whole host of things for the home and garden. Find out more about planting, gardening, and a whole host of other answers to your home and garden questions and queries.