A Fun Way to Grow Hydroponic Radishes


Where! Oh where… did the little radish go? I don’t find it in my salad bowl any more. Kids may not like radishes but they like to see them grow because they grow so fast. I thought if I found a fun way to grow radish kids might try eating them.

So here is a fun way to grow hydroponic radishes for kids. Oh first let me tell you a little about them.

I’m not a doctor or a scientist but I do like to grow things. I have also discovered there are a lot of health benefits found in the little radish. It’s packed with lots of nutrition that most people have forgotten about or perhaps think they just add color to salad.

Just Google “radish nutrition” and you will be amazed at some of the health benefits this little vegetable has. I found out that other than containing the usual vitamins and minerals it is also known as a Cancer preventer.

The radish has a crunchy, peppery, get up your nose kind of taste. It is good to eat it in small quantities until you get use to the taste. I know I didn’t like pickles when I first tried them but now there is always a jar in the fridge. People used to say “What! You don’t like pickles” then look at me like I had two heads.

Now I can see why.

So don’t let the little red radish leave your salad bowl and if it has, you can be forgiven because it’s time to bring it back.

How to Grow Hydroponic radishes

Sparkler White Tip Radish
Sparkler White Tip Radish

There are so many varieties of radishes that you can pick from. The seeds are so cheap you can pick up an assortment from your local supplier, hardware store or Walmart. If you grow several varieties you can then decide what your favorite is.


Cherry Belle Radish
Cherry Belle Radish

The nice advantage of growing radishes from seed is the radish you grow may not be found as a vegetable in your grocery store. Once again you can impress your friends with your unique supply of radishes that your kids grew.


French Breakfast Radish
French Breakfast Radish

Here are a few varieties I found on the seed rack in our local store.

  • Sparkler White Tip Radish
  • Cherry Belle Radish
  • French Breakfast Radish

This will be a general over view of growing hydroponic radishes and the method that I used. It gives you the opportunity to see them grow and you can adapt this method to suite your hydroponic system.

Germinating the seeds

You can use the same method I used to germinate lettuce seeds on the page “how to grow hydroponic lettuce” or this other vermiculite method I used.

What you will need.

  • Plastic Jiffy drinking cup or 2 inch net pot
  • Vermiculite
  • Hydroponic Bubbler (Water Culture) System – bought or home built (see how I built mine here)


Jiffy cup method

The jiffy cup must fit the hole in the lid of your hydroponic system. Prick a few holes in the side and bottom of the Jiffy cup to allow water to enter. Don’t make them too big or the vermiculite will leak into the water.

Radish seedlings
Radish seedlings ready to transplant

Fill the Jiffy cup three quarters full with vermiculite and place it into your hydroponic system. The water level should be high enough to allow water to enter the Jiffy cup, say about a quarter inch from the bottom. This should be enough to allow water to soak the vermiculite.

While this is taking place soak your seeds in water for about an hour or so to give them a bit of a start. Place these seeds on top of the damp vermiculite in your jiffy pot and cover with vermiculite about a quarter to half inch.

That’s it! Cover them with a plastic or glass cup to act as a greenhouse and wait for them to grow.


Two inch “Net Pot” method

Because net pots have large holes in them you will have to line them with paper kitchen towel to prevent the vermiculite from leaking into the water.

Then follow the information above under “Jiffy Cup Method”

Getting ready for transplanting

The next phase is to get your net pots ready for transplanting.

Young radish seedling
Young radish seedling

I purchased a sponge from my local store (any cheap sponge will do).

Cut the sponge so that it’s about half inch thick. Then mark the sponge with a circle the same size as the top of your net cup or jiffy cup (growing cup). This should fit snug into the top of your growing cup. Use a pencil to punch a hole in the center of the sponge.

Next make a cut into the sponge from the edge to the center. This is to allow you to slide the seedling into the center without damaging the seedling.

How to make a grow cup from a Jiffy cup or Net Cup

For the net cup you just have to cut out the bottom. This will allow the radish to grow beyond the depth of the net pot and it will allow it to be easily removed from the net pot.

For the “Jiffy Cup” I cut strips out of the sides but not right to the bottom. The bottom is cut out leaving enough plastic to keep the shape intact. See the photo example.

Ready for Transplanting

When the seedlings have grown to about one inch tall they should be ready for transplanting. Carefully pull the seedling out of the vermiculite. Rinse off the vermiculite and place it into the center of the sponge. Then place the sponge into the grow cup.

Put this back into your hydroponic system and cover again with a glass or plastic cup.

After a couple of days add nutrients to the water then wait for them to grow.

All ready grown up

Radish ready to eat
Radish ready to eat

Here are a few photos of radish ready to eat. You can pull them out of your hydroponic system at any time to see how they are growing.

Inspecting the growth of a radish
Inspecting the growth of a radish

This is ideal for kids to see how they grow and help them understand how things grow from seeds to a full grown plant. One of my radishes I let grow to the flower and then to seed stage which is also interesting for kids to see.


Radish at flower stage
Radish at flower stage

I hope you have found this little hydroponic project interesting enough for you to give it a try.

Hydroponics for kids is a great way to help them understand where our food comes from.

Thank you for stopping by,




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