How Do You Fertilize Orchids in Water Culture?

Learn how to fertilize your orchids in different types of water cultures, so you can apply fertilizers expertly in any water culture.

Sean Stratton | Updated March 8, 2023
healthy orchid in a pot

Step 1: Select a Fertilizer

Select a balanced fertilizer designed explicitly for orchids. You want a balanced ratio of nitrogen, phosphorus, and potassium (N-P-K), such as 20-20-20 or 30-10-10.

Step 2: Moisten the Roots

Spray some water to moisten the roots of the orchid. Do this after the end of the drying period, which is two days for the full water culture.

After spraying, your orchid should be ready to consume the fertilizer. Apply the fertilizer solution to the orchid jar and give it some time so that the roots can absorb the nutrients.

But be careful, limit it only to a couple of hours but make sure it never exceeds a whole day.

Step 3: Replace the Water

Change the water and clean the container regularly. This prevents the build-up of harmful bacteria and keeps your orchids healthy.

Types of Water Culture

If you are a beginner, this section is dedicated to you. And with this section, you can brush up on your knowledge of different types of water cultures. Did you know that you can keep your orchids using three types of water culture, not just one! Take a look at them:

  • Full Water Culture

In this type of water culture, you need to keep your orchid in the water for five days and keep its roots dry for two days. And by the term dry, I mean without water.

Plus, you need to make sure the roots of your orchids always stay submerged in a little amount of water like ⅓ of the height of the jar in the five days of the wet period.

The fun thing is by full water culture, someone might think you need to keep the roots in water 24/7 but that’s totally not true. If you do so, you will end up getting rotten orchids. In reality, the term actually comes from the bottom of the jar containing some water most of the time.

Finally, if the water gets evaporated you need to add more water to maintain the balance.

  • Semi Water Culture

In this type of water culture, there are wet and dry days that come in cycles opposite to full water culture. The cycle should be like this: 2 days in water and 5 days in the drying period. Then you need to repeat the cycle again and again.

One more thing, make a rough measurement of the orchid roots and pour the water on the jar up to ⅔ of the height of them.

  • Semi Hydroponics

This one is a little bit different from Full and Semi water culture. In this method, you need to fill the orchid jar with LECA balls or clay pebbles. And you need to ensure good air circulation inside the jar by drilling holes above the level of water. And that’s pretty much the basics to get started with this method.

Okay, now you have the primary knowledge of different types of water cultures. It’s time to jump into our main discussion; fertilizing the orchids in water culture. Let’s begin the step-by-step process of fertilization with the full water culture method.

Orchids Fertilization in Semi Water Culture

  • Step 1: Picking the Right Amount of Fertilizer

As I already stated, in a Semi Water Culture your orchid gets 2 days for bathing and 5 days for drying out. And the amount of water it needs is comparatively more than full water culture. So, obviously, the only way your orchids can enjoy the fertilizer is by bathing in the water for 2 days.

Though in a semi water culture you use more water, you need to be careful while applying the fertilizer because your orchids will be staying in the fertilizer mixed water for 2 days. And your orchid can get damaged if over-fertilized.

  • Step 2: Apply the Fertilizer

Use a little amount of fertilizer depending on your orchids. Make sure it gets evenly spread to the water of the jar.

  • Step 3: Giving a Break

This step is for giving a break to your orchid! Keeping the orchid in the fertilizer mixed water for too long might not be as healthy and beneficial as you think. This can be the real opposite. So, sometimes giving the orchid a break from fertilized water will be helpful.

Keep the orchid in very low PPM water for a day of the week to give it a holiday.

Okay, that’s quite everything about how you can fertilize your orchids in a Semi Water Culture. Now, let’s move on to fertilizing the last water culture method; Semi Hydroponics.

Orchids Fertilization in Semi Hydroponics Water Culture

I have already discussed that in Semi Hydroponics, you need to use LECA balls. The thing about these balls is that they absorb water and this means that your orchid’s roots will be in contact with water all the time, directly or indirectly.

And you can say this as constant fertilizing because the LECA balls are going to absorb the fertilized water and gradually release it. So, your orchid will slowly receive nutrients all the time. But I have been saying a lot of times that excessive fertilization is not good for your orchid.

So, what’s the solution? It’s simple… you just need to ensure the orchid jar is thoroughly washed before you use the fertilizer. What this will do is: the water will remove the excess salt absorbed by the LECA balls and ultimately save you from worrying about excessive fertilization. Here is how you can do it in a step by step process:

  • Step 1: Rinsing Out

Before applying the fertilized water to the jar, rinse it out thoroughly with fresh water. Make sure the jar gets overflowed with the water so that there are no excessive minerals remaining on the jar.

One more thing, as we are talking about Semi Hydroponics, there will be holes in the jar. So, to make sure all the excess salts get rinsed out even from the top portion of the jar, you should block the holes so that the water overflows through the mouth of the jar and everything gets washed properly.

  • Step 2: Applying the Fertilizer

After you are done washing the jar properly, it’s time to add the fertilized water to the jar. And last but not least, always remember to give your orchid a break from fertilizers once a month just like the way in semi water culture.

Finally, you are all caught up with fertilizing your orchids in different water cultures.

The Bottom Line

I discussed with you pretty much the basics of all three types of water culture methods and the fertilization techniques on them.

Keeping this guide in mind, you can apply fertilizers to your orchids, no matter what type of water culture you are using to keep them. So, what are you waiting for? Start feeding your hungry orchids.

Written by Sean Stratton

Sean Stratton

Hi, I'm Sean, the senior editor here at Fertilizer Pick. I grew up on a farm in North Carolina and have grown fruits, vegetables, and trees since childhood. While I no longer live on a farm today, I still enjoy spending time on my garden and sharing my knowledge with friends and fellow garden enthusiasts.