How to Fertilize Your Ferns

3 Materials
1 Hour

Have you ever wondered how to fertilize your ferns?

Do you wonder why your ferns look so sad halfway through summer?

I am going to show you the easiest way to get your ferns to stay as green as they were the day you purchased them!

I am actually willing to bet your ferns will be so happy, they will be even more green than the day you brought them home.

THAT MEANS ALL SUMMER LONG……AND ALL THE WAY THROUGH FALL for all of you zone 8 gardenistas out there in this world!

Are you ready for my secret?

Here goes nothing…..

Fish Fertilizer!!!!!!

Fish fertilizer is an excellent source of nutrition for your ferns. This fertilizer is safe around children and pets. It is also a low cost method of fertilization. This fertilizer strengthens the fern’s root system. And, it improves the organic matter in the soil. The results are immediate…… you will most likely see improvement within 24 hours.

When spring has sprung each year, I pull all of my ferns out of the greenhouse. My first order of business is to give them a nice bath in some fish fertilizer. I repeat this process once a month the entire growing season my ferns are out of the greenhouse. I am a Texas Hill Country Texas gardenista. So, this time frame spans from the middle of March through the middle of November.


5 gallon bucket

water hose

Alaska Fish Fertilizer

Instructions to Fertilize Ferns

  1. Water ferns deeply before you fertilize so that you do not risk burning the roots.
  2. Make sure the lid to the fish fertilizer is on tight.
  3. Give the fertilizer a few heavy duty shakes to mix it up.
  4. Pour enough liquid fish fertilizer into the bottom of the bucket so that it completely covers the bottom of the 5 gallon bucket. I do not measure exactly. Caution: When I first pour it into the bucket the smell is noticeable, but it quickly subsides – or maybe I am just delusional from the smell. Actually, this particular brand of fertilizer contains a deodorizer that really helps diminish the smell.

  5. Fill the bucket with water.
  6. Do not turn the hose on full blast as this will cause the fertilizer to splash out and hit you in the face. This is not something you want to happen.The gentle water pressure from the hose will mix the fish fertilizer into the water. However, feel free to use a yardstick to give it a stir. A fallen branch from a tree works well in a pinch.
  7. Slowly pour this mix over each fern. One 5 gallon bucket will adequately fertilize three of my ferns. However, Fronda, my whopper fern, gets one bucket all to herself. Repeat this process depending on how many ferns you own. Currently, I own 12 ferns so I repeat this process five or six times depending on how big they have gotten over the last growing season.

A Few Notes on J Dub’s Fern Fertilization ….…..

I realize that you might be hesitant to try this because you are worried about the smell. I am telling you that the smell is more than worth it. And, it doesn’t last long. Your ferns will thrive on this liquid gold. You can almost see them turning a deep shade of green right before your eyes as you pour the mix onto them. The next day, neon green new growth magically starts to appear. I have found nothing else that works nearly as well as this fish poop.Need more proof on the smell fading fast….Some of my ferns are so large that I can not easily move them. Because of their enormous size, I have to fertilize them directly on my patio.

The smell evaporates within the hour. And yes, you can enjoy sitting on your patio.

P.S. This fish fertilizer works well on other green leafy container plants as well.Just do not fertilize them in the hot afternoon sun.

A macho fern on my back porch.

Fertilizing the ferns out in the courtyard

All you need is an empty five gallon bucket, a water hose, and the fish fertilizer. Pour the fertilizer into the bottom of the bucket (enough to barely cover the bottom) and gently add water from water hose.

Fronda, my largest fern.

On the large ferns, I use one bucket of fertilizer.

Pour the fertilizer in the bucket so that it covers the bottom of the bucket.

Gently spray water into the bucket to fill it. This mixes the fertilizer into the water.

Resources for this project:

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Jennifer Williams
Want more details about this and other DIY projects? Check out my blog post!

Frequently asked questions

Have a question about this project?

3 of 4 questions
  • Jennifer Jennifer on Apr 09, 2021

    Would you use this on ferns you have inside your house? I have two and they hate me.

  • Vrider Vrider on Nov 21, 2021

    Do these ferns survive winters?

  • Vrider Vrider on Nov 21, 2021

    I should have been more explicit the fern is huge in a pot outside and extremely heavy - how do I protect it in the winter?


Join the conversation

3 of 4 comments
  • Jennifer Williams Jennifer Williams on Apr 07, 2021

    You pour the mixture into the pot - some will get on the frond - but you want to get it to soak into the dirt in the pot before it drains out of the bottom.

  • Jeri Jeri on Apr 07, 2021

    They look fantastic! I have hanging baskets and need to report this year. Any suggestions as to kind of pot and shape that works best?

    • Jennifer Williams Jennifer Williams on Apr 09, 2021

      I don’t use hanging baskets because mine dry out way too fast. I will do some research and see if there is anything new out there on the market that helps them retain moisture better.