Best Homemade Fish Emulsion

Fresh sardines.

Fish emulsion is a seafood-based source of organic plant food. These include nitrogen, phosphorus, potassium, amino acids, proteins, and micro-nutrients. It is proven effective in feeding nutrition to your soil and plants.

Also, it provides immediate benefits to the plants. And has a long-lasting effect to help increase microbial activity underneath the soil.

And the best part is that creating a fish emulsion at home is simple. But you might be asking, why bother messing around with homemade versions when you can buy fish emulsion straight from the store?

The reason is, most commercial fish emulsion products use fish scraps as the primary ingredients.

Homemade versions are often made of whole fish. It also means the fertilizer has more protein, more oil, and more bone, making the benefits way more effective, both to the soil and plants.

So, let’s help you out with making the best homemade fish emulsion for your garden.

All You Need To Know About Homemade Fish Emulsion

What Is Fish Emulsion?

Plastic measuring jug full of concentrated homemade fish emulsion.
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Fish emulsion is made from raw fish or fish byproducts of the fishing industry. It provides an NPK ratio of 4-1-1 and other elements, which are beneficial to green leafy plants and soil microbes.

It is efficient in helping plants grow robust, healthy, and can make blooms more vibrant and last longer.

The proper use of fish emulsion can cause bountiful yields, particularly in areas with cooler climates. Unlike compost made of manure that breaks-down slower in colder months, fish fertilizer remains at a steady rate.

However, incorrect use of fish fertilizer may burn plants, especially young and tender potted plants.

Benefits of Homemade Fish Emulsion

Four unripe tomato fruits.

  • Strengthen Microbial Activity

Unlike synthetic fertilizers that are readily available for plants to absorb, the all-natural fish emulsion contains nutrients that must first be digested by microbial organisms in the soil before they are available as plant food.

  • Help Plants Grow Strong and Healthy

Active microbes in the soil gradually break down nutrients, making it available for plant roots to use.

And this microbial activity helps increase the amount of organic matter in the soil, particularly in non-organic garden soil, making plants strong and healthy.

  • Help Microbes Aerate the Soil

What makes this activity even more amazing is that when beneficial microbes become active, they work hard night and day to loosen the soil. Their process of aerating the soil promotes a strong and healthy rooting system.

  • Help Plants Withstand Pests and Diseases

Fish fertilizer is not only an excellent source of primary nutrients such as nitrogen, phosphorus, and potassium. It also provides secondary nutrients like calcium for the plants to thrive.

Generally, plants that receive a balance of primary and secondary nutrients are healthy and can resist pests and diseases.

Unpleasant Smell

Some people find fish emulsion stinky. And many opt for pre-made products to avoid the smelly and messy process of fermenting the fish plant food.

Yes, the homemade version smells quite unpleasant, and making it at home means you have to deal with both the unpleasant smell and the messy process. However, this is normal when the process of decomposition stimulates fungal and bacterial content in the fertilizer. You will get use to it after your first time of use.

DIY Homemade Fish Emulsion

Making your fish emulsion at home is more efficient, beneficial, and cheaper than commercial products, and you can make a big batch all at one time.

Here’s how to make it.

You’ll need:

  • 5-gallon plastic bucket with lid
  • Garden Hand Rake (a tool to stir the mixture)
  • 18″ x 18″ Window Screen
  • Crabs or Fish (Any fish will work)
  • Sawdust
  • Molasses


  • Toss about an inch-high layer of sawdust at the bottom of your plastic bucket. (You can also use dried leaves, grass clippings, and other brown organic matter.)
  • Lay crabs, fish, or unused fish scraps on the 5-gallon plastic bucket about 2/3 of the way full.
  • Some DIY enthusiasts throw fish to the blender to ground it up for fast fermentation. (optional)
  • Adding molasses about 1/4 to 1/2 cup will help control the stinky odor.  When molasses is not available, you can use about 3:1 ratio of unrefined sugar instead. (The fish and sugar ratio is 3Kg of fish is to 1Kg of crude sugar)
  • Adding chopped or powdered seaweed or kelp will provide more nutrients into the fertilizer. (optional)
  • Adding Epsom salts is also fine if your plants need an extra dose of sulfur and magnesium. (optional)
  • Fill the bucket with water and ensure materials in the bucket are all covered.
  • Use non-chlorinated water to avoid killing beneficial microbes. Let tap water sit several hours to allow chlorine in the water to disperse.
  • Stir the mixture thoroughly until all the materials are well incorporated.
  • Cover the brim with a window screen before covering it with a lid. (The window screen will prevent adult flies from getting inside the bucket. Or else you must deal with a bucket full of maggots.)
  • Cover the bucket with its lid. (Do not cover it too tightly to avoid the build-up of pressure as it brews to avoid explosion)
  • Let it ferment by leaving the bucket under the sun.
  • Stir the mixture every couple of days for at least two weeks. However, about a month of fermentation may create a more concentrated solution.
  • Adding two tablespoons of molasses every time you open to aerate and stir the mixture will help lessen the foul odor because of fermentation. (optional)
  • The mixture will smell quite unpleasant in the first week of fermentation. And when you need to open and stir the fertilizer, it’s better to do it at night.
  • Avoid opening the bucket during the day to avoid flies swarming towards the open bucket.
  • In the second week, the smell of your mixture should be like that of fish sauce common in Asian cooking.
  • In the third and fourth weeks, the mixture is almost liquified, making it easier to stir. The odor will also be less offensive, and the fertilizer will appear darker because of molasses.
  • When the fertilizer is fully fermented, it should be ready to use.
  • Extract the solution and catch it into another bucket.
  • The collected extract is your fish emulsion.
  • You can either use the strained fish scraps and leaf litter when you brew another batch or throw them in your compost bin.
  • The concentrated fish emulsion is now ready to use. Dilute with water before using it.

How To Use Homemade Fish Emulsion

Water vegetable plant with thinned fish emulsion.

Fish emulsion is both exceptional as a drench or foliar fertilizer. Foliar application is essential if your plants demand more nitrogen, especially during the vegetative stage. It is a fast-acting fertilizer where plants can absorb the nutrients immediately.

  • Prepare a large container in which you can dilute the fertilizer with water.
  • Dilute the emulsion with the ratio between 2-3 tablespoons to every gallon of water.
  • Mix the fertilizer thoroughly.
  • To use as drench fertilizer, fill your watering container with the liquid solution, and water the plants overhead.
  • Alternatively, water the plants at the soil level and drench the soil thoroughly to feed the roots substantially.
  • Feed plants during the cooler parts of the day, preferably at night, to avoid the possibility of plant burns.
  • Repeat the feeding process with your plants twice a week for optimum growth.
  • To use as a foliar spray, apply directly to leaves, such as on fruit trees, flowering plants, and vegetables for immediate absorption.
  • As you may expect, fish emulsion smells bad. Therefore, do not apply on houseplants unless it is okay for you if your home smells like a fish market.  Although the fish aroma naturally dissipates in two days.

How Long Does Fish Emulsion Last?

homemade fish emulsion.
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Fish emulsion can last for at least a year when stored properly. Take note that the fertilizer heats up quickly in storage, so keep the concentrated solution at room temperature.

Use diluted versions as soon as possible as it ferments more. You will find that an old diluted mixture clogs a water sprayer often when used. Therefore, mix only a small quantity sufficient for a single application.

Also, ingesting the fertilizer can cause nausea, abdominal cramps, and vomiting, making it essential to keep containers out of reach of children and pets.

And during foliar spray application, don’t forget to use eye protection. The fertilizer can cause eye redness, burning, and irritation. Also, wash your hands thoroughly after applying the fertilizer.

Final Thoughts On Making Your Own Fish Emulsion

Most people are now becoming more aware of environmentally friendly options, turning to organic over synthetic chemicals to help promote ecological diversity.

And it does not take a degree in soil conservation to realize the benefits of fish in bringing back the healthy conditions of the soil.

Homemade fish emulsion costs way cheaper to brew in large quantities. It also contains aerobic bacteria and fungi essential to the plant’s healthy growth. Moreover, it boosts the plant’s resistance against pests and diseases.

Such living organisms are not found in commercially produced products to avoid the container from expanding and exploding while on the shelf storage.

Fish emulsion is known for its high organic nitrogen and soluble P and K benefits with the immediate result- be it as a drench or as a foliar feed.

There you have everything you need to know about fish emulsion. If you have any questions, don’t hesitate to ask below!

About Benita Abucejo

Hi there! My name is Benita Abucejo. What can I say? I truly love spending my days in the outdoors, specifically in the garden. Gardening has always been a strong passion of mine since I was a little girl. It has brought me so much joy and happiness that it is definitely safe to say that I will be a gardener for life. For a period of time, I was able to work with people who are into home gardening and I found it to be quite beneficial to my physical health, as well as my mental well-being. Here at Seasonal Preferences, I am going to share with you my experience and ideas so that you can fulfill yourself with the same satisfaction and happiness. Of course, if you have ideas, I would love to hear those as well! Being creative in the garden can really be quite fascinating so let's share our experiences and be the best gardeners we can be. With that being said, thank you for dropping by and please leave me a comment on one of my posts if you would like to get in touch!

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