Hydroponic culture cat grass

I tried several types of cat grass kits. Every kit comes with a soil and I used the soil every time. But I wondered why I always get mold on soil and why not every seed grew up. Do I really need soil?

When I was kid, I used a hydroponic culture to grow radish sprouts. I thought I could use this way for cat grass too. I googled hydroponic cat grass on Internet and I found a Japanese person planting cat grass using a hydroponic culture. He got a hint from a sprout containers which is popular in US. Oh, right, I knew that kit!

I checked sprout containers, but every container was short with a stackable design, because they don’t want to grow more than sprout. I can’t use a sprout container for cat grass and it was a little bit expensive for a trial. But I got a good information from them, they wash the seeds twice in a day in order to prevent mold. I thought, I could use this method for hydroponic culture cat grass.

I couldn’t find another nice container for hydroponic culture around my house, so I decided to make a container from a plastic cup.



  1.  Plastic cups (2-3)
  2.  T pin
  3.  Hammer
  4. Wheat grass seeds

I chose a short and wide cup. I stack three cups. The top cup has a lot of holes on the bottom. The middle cup has no bottom because this cup is for making enough space between the top cup and the bottom cup. I didn’t do anything for the bottom cup.


Step 1: Make holes on the bottom for top cup.

You can use nail or some kind of thick needle instead of T-pin. You have to make enough wide holes so that grass roots can go through them. The hammer is used to hit the nail, but this is optional but it’s easy to make holes. I tried an electric drill and it was easy to make holes, but I had to cut out small burrs from each hole. I recommend using T-pin.


Step 2: Cut out the bottom for middle cup.

I cut out only the bottom and kept the side wall. The side wall reaches the bottom of the bottom cup.



Step 3: Fill with a lot of water and seeds.

You need to soak the seeds with enough water. Then put it in a dark place. I put it in a kitchen cabinet.


Step 4: Change the water twice a day.

The seeds will absorb a lot of water. You can decrease the water amount when the seed sprouts a root. But still you can keep in the dark place.


August 24, morning

The water amount is between the bottom cup and the top cup like below.



Step 5: Move to a sunny place.

You can see sprouts after you repeat Step4 for a couple days. Now it’s the time to give them sunlight.


August 25, morning


Step 6: Keep changing the water twice a day, everyday.

The first picture was taken August 25, night. The second picture was taken August 27.

20150825_213053914 20150827_122230436_iOS 20150827_122947785_iOS

Oh, It looks so purrfect.


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