Fish emulsion organic fertilizer

Fish Emulsion Fertilizer – Tips For Using Fish Emulsion On Plants

Fish emulsion benefits to plants and ease of use make this an exceptional fertilizer in the garden, especially when making your own. For more information on using fish emulsion on plants and how to make fish emulsion fertilizer, please continue reading.

What is Fish Emulsion?

Using fish for fertilizer isn’t a new concept. In fact, settlers at Jamestown used to catch and bury fish to use as fertilizer. Organic farmers across the globe use fish emulsion in place of toxic chemical fertilizers.

Fish emulsion is an organic garden fertilizer that is made from whole fish or parts of fish. It provides an NPK ratio of 4-1-1 and is most often used as foliar feed to provide a quick nitrogen boost.

Homemade Fish Emulsion

Making your own fish emulsion fertilizer may seem like a daunting task; however, the smell is well worth it. Homemade fish emulsion is cheaper than commercial emulsions, and you can make a big batch at one time.

There are also nutrients in homemade emulsion that are not in commercially available products. Because commercial fish emulsions are made from trash fish parts, not whole fish, they have less protein, less oil, and less bone than homemade versions that are made with whole fish, making homemade fish emulsion benefits even more amazing.

Bacteria and fungi are necessary for soil health, hot composting, and disease control. Homemade versions contain lots of bacterial microorganisms while commercial emulsions contain few, if any, microorganisms.

A fresh emulsion fertilizer mixture can be easily made from one-part fresh fish, three-parts sawdust, and one bottle of unsulfured molasses. It’s usually necessary to add a little water too. Place the mixture in a large container with a lid, stirring and turning daily for about two weeks until the fish are broken down.

How to Use Fish Emulsion

Using fish emulsion on plants is a simple process as well. Fish emulsion always needs to be diluted with water. The usual ratio is 1 tablespoon of emulsion to 1 gallon of water.

Pour the mixture into a spray bottle and spray directly on plant leaves. Diluted fish emulsion can also be poured around the base of plants. A thorough watering after fertilizing will help plants take up the emulsion.

** For an illustrated example of this recipe, check out the The Unconventional Farmer’s Blog here. The blog has all kinds of good stuff, sign up to get the updates via email!

Fish fertilizer is an awesome product for promoting plant growth. It’s high in Nitrogen for growing plants, can be naturally produced, and is an awesome food for microbes! Fungi love this stuff. Fish fertilizer can be expensive in the store, but it is easily produced at home. This is a great recipe for making your own fish hydrolysate fertilizer. First lets look at the two main types of fish fertilizer:

Fish Emulsion

Fish emulsion fertilizer is made several different ways depending on who is making it. The important thing to know is that fish emulsion goes through two stages of processing. The first stage breaks down the fish parts using enzymes, proteases, or chemicals. Then, and this is the important part, heat is used to break it down further and allow oils and other things like amino acids to be more easily removed. It’s this second stage of processing that makes fish emulsion less advantageous than fish hydrolysate. Fish emulsion fertilizer lacks many oils and proteins that fish hydrolysate fertilizer has in abundance. So let’s look at that!

Fish Hydrolysate

Fish hydrolysate fertilizer generally starts out the same way as fish emulsion. It gets broken down using enzymes, proteases, or chemicals. However, fish hydryolysate doesn’t undergo the heating and skimming process that you get with the fish emulsion. The higher quality fish hydrolysates only undergo “cold-processing” which just means they are never heated enough to break down significant amino acid chains. Good fish hydrolysate also retains the fats and oils that microbes love!

Our Fish Fertilizer Recipe

This method of making fish fertilizer is awesome because it is a cold process, chemical-free, completely organic way to make fish fertilizer right at home. While fish emulsion lacks beneficial ingredients vital to the final product, this fish hydrolysate recipe preserves all those active ingredients. You don’t want to miss out on those oils that microbes love. Try this recipe in the yard or in a raised bed garden (If you are a novice gardener you can view videos online to learn how to plant a raised bed garden)

How to make your own fish fertilizer:

  1. Buy a fish.

TIP: Any kind of fish will work. In fact, you might as well use trash fish, or fish discards like fish heads, guts, etc. I like to use whole fishes though as I think that makes for a better product.

  1. Now, ideally you would throw the fish into a blender to mash it up into little pieces. I cut my fish into 8ths or so and then chuck it into my kitchen blender but I’m a bit of a caveman. If you’re squeamish, buy a separate blender for this, just make sure it is powerful enough, mine is 500W and works fine for small-medium size fishes. Remember, the finer the fish bits, the more effective the fermentation.
  2. Add water. You can use a simple guide of 3:1 – 3 parts water to 1 part ferment material. 1 roughly 8in tilapia comes to about 500mL when ground up, so I add about 1500mL water.

TIP: ALWAYS USE NON-CHLORINATED WATER. Chlorine kills microbes. Simply let your chlorinated tap water sit for several hours, allowing the chlorine to dissipate. I let it sit overnight generally.

  1. If you are using a blender, blend up the mixture. The water helps keep it loose so it blends much betterafter you add the water.
  2. Add lacto bacilli to blended fish mixture. I use 2tbsp per L. You can use more or less if you want. 2tbsp/L is plenty though. See our lactobacillus recipe for proper preparation and dilution of your lacto serum.
  3. Add 1/3 parts sugar. This should be 1/3 the amount of fish you’ve added. Sugar will be either molasses or normal cane sugar.

TIP: Try not to use cane sugar since it is chemically bleached. Raw(unrefined) sugar like muscovado is best. In the Philippines we use molasses because it is cheap, but any glucose source works – syrup, honey, etc. Just use whatever is cheap. Glucose gives microbes energy. Whatever you have access to cheaply, go for it.

  1. If using sugar, the equivalency is about 1KG sugar = 1L solution. So if you have 500mL like my tilapia, you want 1/3 of that in sugar. You’d use about 167g sugar, or roughly ¾ cup.
  2. I blend the whole mixture up a bit. It’s good to have it as fine as possible.
  3. Up to you how much you blend it, I blend until I don’t hear so many bones crunching in the blades of the blender.
  4. Now you have liquefied fish, sugar, and lacto. Pour this mixture into a container. Loosely cover the container. No need to seal, because the container will explode as CO2 is released by fermentation. You just want to make sure other things don’t get into it. I use a container with a lid and loosely screw the cap on top (just make sure you don’t seal it because it WILL explode).
  5. The process takes anywhere from 3 weeks to over a month. How do you know its finished? By the smell.
  6. You know when it’s done when there is no smell anymore. During fermentation there is a nasty smell, but once completed, there will be almost no odor. You can open it, and put your nose right up to it. Take a whiff. Nothing but a faint vinegar smell. Now you know its done. Congratulations! You’ve made your own Fish Hydrolysate!
  7. Now, usually I transfer it to a smaller container, usually just a smaller water bottle, just for convenience. At this time, I use a strainer and a funnel to strain the bones and scales out of the hydrolysate. But don’t expect a lot. From a whole 8-10in tilapia, you will only get a little tiny pile of bones/scales. They will feel kind of rubbery, not brittle. Throw these in the compost pile or garden, they are excellent fertilizer and microbe food, already inoculated with microbes!
  8. Leave the cap on the strained concoction loose until you see no more little bubbles forming. Then cap it and store it for use as your own natural fertilizer.

How to use this fish fertilizer:

Mix 2tbsp/gal for applications.


  • Use as a soil drench as opposed to foliar spray.
  • Inoculate compost to boost fungal population. This is huge – major growth booster of fungus.
  • Use in compost teas to boost fungal growth, add Nitrogen. Use at ¼ strength for this application(1/2 tbsp per gal).
  • Mix in water when watering plants, as a natural fish fertilizer and to enhance populations of micro-organisms in the soil

All You Need to Know About Fish Fertilizer

Centuries before scientific soil research began, Native Americans understood the value of fish as fertilizer. While preparing the ground to plant corn, indigenous people placed a small fish in the soil. They mounded fresh dirt on the buried fish and planted a corn seed.1 Throughout the growing season, the fish slowly decomposed, feeding the crop until harvest.
Native Americans were correct about the nutrients in fish, but thankfully you no longer have to catch your own for each seed you plant. As you ponder the fertilization options available for your garden, consider the unique features and benefits of fish fertilizer.

How is Fish Fertilizer Made?

Fish fertilizer is made from whole fish and carcass products, including bones, scales and skin. Rather than let unusable fish products go to waste, these items are converted into nutrients for the garden. Different types of fish, such as menhaden and anchovies, are ground into a slurry. This product is then processed to remove oils and fish meal, which are used for other industries. The liquid that remains after processing is fish emulsion. After straining out solids, sulfuric acid is added to lower the pH, preventing microbes from growing. The fish fertilizer is then stable to package and ship for use in the garden.

What are the Benefits of Fish Fertilizer?

Some quick release synthetic fertilizers offer immediate nutrients in the garden because they are processed to be readily available for plants to absorb. All-natural fish fertilizers are processed differently in the soil, because they contain nutrients that must first be digested by organisms, such as bacteria, earthworms and fungi, before they are available for plant roots to use.2 All of this microbial activity enhances the strength and vigor of plants by increasing the amount of organic matter in the soil. Fungi and bacteria break down nutrients to make them available to plant roots, and then loosen the dirt as they travel, reproduce, process nutrients and decay, leaving soil aerated with improved levels of organic matter. Plant roots grow faster and stronger in this light, airy soil that is teeming with life.2
As fish fertilizer improves soil health, it also increases soil fertility by providing the primary nutrients necessary for plants to thrive. Fish fertilizers offer a source of burn-free nitrogen, along with the other primary nutrients of phosphorus and potassium. Unlike synthetic options, they may also provide secondary nutrients, such as calcium, which is found in Alaska dry fertilizers.3 Plants that receive a balance of primary and secondary nutrients experience strong and steady plant growth, leading to vigorous plants that can better withstand disease and pest issues. 4

How do You Use Fish Fertilizers?

With a variety of options available, there is a fish fertilizer for your specific needs. Alaska Fish Fertilizer 5-1-1 is OMRI listed, so it can be used in outdoor organic gardens. For indoor and outdoor plants, Alaska dry fertilizers are low-odor, dust-free options.

Liquid Fertilizer

To use Alaska Fish Fertilizer 5-1-1 on outdoor annuals, bedding plants, vegetables and herbs, shake well, and then mix 2 tablespoons of fertilizer with 1 gallon of water. One gallon will cover 25 square feet of soil. For berries, perennials, roses and vining plants, mix 3 tablespoons of fertilizer with 1 gallon of water for every 25 square feet of soil.

Add Alaska Morbloom Fertilizer 0-10-10 to promote vigorous root growth on flowering plants. Mix 1 tablespoon per gallon of water for every 25 square feet of annuals, bedding plants, vegetables and herbs. For perennials, bulbs, roses, shrubs and vines, mix 2 tablespoons with one gallon of water for every 25 square feet of soil.

Regardless of your choice of liquid fertilizer, apply every 3 weeks during the growing season.

  1. Designate a five-quart bucket for the emulsion. It will always smell like fish after this, so you likely won’t want to reuse it for something else.
  2. Get fish scraps from a store, or put your own in.
  3. Layer them in with leaves until the bucket is two-thirds full.
  4. Top the layers with a fish layer.
  5. Cover the mixture with water, leaving a few inches of space on top of the bucket.
  6. Seal the bucket and tuck it away. Check it each day for a week, and then every few days, to see if the gas is building up. When you notice gasses begin to form, you should stir the mixture once a week.
  7. It should sit for about a month. If you live in a warmer climate, it may tend to break down faster.
  8. To use the homemade fish emulsion, strain out leaves and fish bits being careful not to allow it on your skin or clothing. Dilute about 5 ounces of the emulsion into 1 gallon of water, or dilute 30 ounces of it into a 5-gallon bucket. Apply to the garden.
  9. Don’t get rid of the leftover scraps. Add more water to the bucket and start the process again. You can typically use used material about three times.

How to Make Your Own Fish Emulsion Fertilizer

Fish emulsion is a good fertilizer for lots of garden vegetables—and other plants, too. It has an N-P-K ratio of about 5-2-2, and has micronutrients, too. Store-bought fish emulsion is made from the by-products of fish used for another process, like fish oil or canned fish. Using fresh fish that still have all their parts intact should be even better than the commercial stuff.

You can make homemade fish emulsion at home in a bucket—or several buckets if you have a lot of fish. I’ve done this with scraps I had from cleaning fish I caught, but it should work fine with whole fish, too. Fill the bucket about 2/3 of the way full by layering fish scraps and brown organic matter (like leaf litter) in equal parts. Fill the bucket with water to cover all the material, cover it with a lid, and keep it out of the sun. If you’d like, add molasses and seaweed to get more nutrients in the emulsion. Stir the mixture every few days for several weeks, and then it should be ready to use.

Pour off the water and catch it in another bucket—this is your fish emulsion. You can use the remaining fish scraps and leaf litter to brew another batch, or just put them in your compost pile or worm bin.

To use the fish emulsion, dilute it with water. Use about a cup of emulsion to a gallon of water. The dilution can be used to pour on garden soil or to spray on leaves.

(This is an updated version of an article that was originally published on March 30, 2015. The author may not currently be available to respond to comments, however we encourage our Community members to chime in to share their experiences and answer questions!)

(Visited 26,930 times, 3 visits today)

Have you ever heard of or used fish emulsion fertilizer? What is fish emulsion? Healthy garden plants are a result of good quality soil, plant food, sunlight, water and of course sufficient nutrients for their health.

There are plenty of organic matter or organic products you can use to fertilize your plants with:

  • Compost
  • Manure
  • Weeds
  • Worm castings
  • Kelp
  • Seaweed Fertilizer Extract

… and so on.

Down at the garden center, you’ll often find special fertilizers for growing tomato plants and roses like Knockout rose bushes.

However, there are also good organic items and supplements to consider – fish emulsion fertilizer is a good example.

Fish emulsion is a liquid fish fertilizer like this from Neptune Harvest made from byproducts of the fishing industry.

It is beneficial for leafy vegetables and fruits we grow.

It is high in nitrogen and sold as a concentrated liquid which gardeners dilute and use. It has a typical fishy smell but now-a-days, deodorized versions are available easily.

What Ingredients and Nutrients Are In Fish Emulsion?

We all are aware that the fertilizers have the ingredients Nitrogen, Phosphoric acid and Potassium and is denoted in N-P-K ratio number.

This ratio tells the percentage by weight of each of these three elements.

Generally, fish emulsion plant fertilizers have a ratio of 5 :2:2 or 5:1:1.

These liquid organic fertilizers may provide the ingredients which your soil might lack and are necessary for a rich and balanced growth in your garden.

Fish emulsion also provides trace elements like:

  • Calcium
  • Magnesium
  • Sulphur
  • Chlorine
  • Sodium

… which plants require in micro quantities.

How Do You Use Fish Emulsion In The Garden?

Fish fertilizer for plants:

You’ll need:

  • A bottle of fish emulsion (either store-bought or home-made)
  • A clean bucket

The procedure is very simple. For every 1 gallon of water mix 3 tablespoons of the fish emulsion concentrate. Increase this quantity with the number of gallons water you will be using.

That’s all there is to it. Your fish fertilizer is ready to go.

In the garden, apply the fertilizer as a foliar feed like you would a liquid fertilizer by watering plants with the solution through its leaves. It’s recommended to use around 1/2 gallon per tomato plant for example.

As simple as the process is of using fish emulsion on plants, there are reasons for using organic fish emulsion fertilizer over other fertilizers.

  • Organic fish emulsions are produced from unused fresh fish parts, and are natural resources which will otherwise be wasted.
  • They contain ample Nitrogen- Phosphorus- Potassium which are essential plant elements.
  • The micronutrients like Calcium, Magnesium, Sodium etc. which are constantly replenished and needed by plants.
  • Fish emulsion for plants can be used at any point of time as an all-purpose garden fertilizer.
  • They are mild and there is less chance of damaging/ burning the plants.
  • It can be used as a soil drench as well as a foliar spray. No fancy chemical fertilizer injector needed a hose-end sprayer will work just fine.
  • They are beneficial to the plant but do not cause any harm and contamination of the environment like the chemical varieties.
  • Some use it in the dry fertilizer form called a fish meal and add it to the compost pile the same way bone meal fertilizer powder is added.

The nutrients supplied by fish emulsions make the plants stronger and pest resistant. The addition of lavender oil has helped take the fishy smell out with a deodorized option is available.

One additional benefit of fish emulsion is, that plants will not be overfeed.

The nutrients help increase soil health and soil microbes.

How Often Should Liquid Fish Emulsion Be Applied?

Since the fertilizer acts fast on providing nutrients, more frequent applications are required.

Many plants grown outdoors are watered twice per week. Research has shown, that the application of half ounce of fish emulsion mixed with one-gallon water applied twice weekly helped plants grow vigorously.

Check The Percentages

Before feeding plants with fish emulsion, always check the nutrient levels currently present in the soil to avoid overfeeding. Follow the instructions on the packet, if using store brought emulsions.

How To Make Your Own Homemade Fish Emulsion Fertilizer

Store brought emulsions are dependable and convent, but you can definitely make your own. The homemade solutions tend to be pure and have more nutrients.

Store brought products are made from various fish parts – blood, tails, heads, insides etc. Some use raw fish some use cooked. Some may add seaweed to add additional nutritional value.

Homemade emulsions are rich in nutrients as well as in fungi/ bacteria which are also needed. You’ll find different recipes for making fish emulsion fertilizer.

To make your own liquid emulsion fertilizer:

  • Half 5 gallon bucket of Composted Manure
  • 4-5 Cans of Sardines in water or fish oil
  • Half Cup Black Strap Molasses (some recommend unsulfured molasses)
  • Handful Epsom Salts
  • Fill with water
  • Cover with lid and cut holes in lid so it can breath (cover holes with screen)
  • Stir Daily for 2 weeks, then strain solids off
  • Use liquid as you would store bought Fish Emulsion Fertilizer.

Using a fish emulsion fertilizer is a excellent organic option to fertilize your outdoor plants. DO NOT use on your indoor plants. The reason – SMELL!

The next time you find yourself preparing to throw out spoiled fish or fish remains, stop for a second and reconsider. Fish makes a very good natural fertilizer for nitrogen and trace minerals. In fact, it works so well that many Native American horticulturalists buried a fish at the base of each crop plant. Check out the video below!

How to Use Fish Scraps as Fertilizer

You can grind your fish parts up to make your own fertilizer. We recommend using a hand grinder or stick blender rather than your kitchen blender. It’s easier to clean and can be used as gardening tool and not the kitchen. Then work it into the soil, or you can bury chunks of fish at the roots of your plants. Be aware, however, that dogs and some wild animals are fond of strong smells, and may dig up your garden if you use fish as fertilizer. Be sure to bury it deeply, or fence in your garden.

If you don’t want to bury fish scraps, try making your own fish emulsion. There’s a link below.

Or, add ground up fish bones and skin to your compost pile, adding nitrogen and trace minerals to your compost. Keep in mind fish scraps can increase the chance pests will find your compost. Here’s a detailed PDF from Louisiana Cooperative Extension Service: Composting: A Disposal Method for Fish Waste. This is a great resource if you know an angler or fish yourself and want to set up a compost pile for fish scraps.

Where to Find Fish Scraps

If you are not an angler, don’t worry. There are many ways to find fish in your community.

Try a fish market and ask for their scraps. Most will be happy to give them to you. It’s just like asking the coffee shop for their used grounds.

If there is not a fish market close by, try a high end market, grocery store or restaurant with a great seafood selection and see if they have any wastes. They are more likely to clean their fish and have scraps or even fish heads.

Scraps you’ll want to ask for include: intestines, liver, gall bladder, heart, fins, tail, scales, fish heads/gills and bones.

Want to learn more about using fish as fertilizer?

Make Your Own Complete Fertilizer from University of Alaska Fairbanks Cooperative Extension Service: See how to make fish emulsion here.
Organic Fertilizers: Fish Emulsion from Colorado State University Extension Program
Creating Community Gardens from Northwest Indian College Cooperative Extension: Great information on building soil with fish and shellfish.

Leave a Reply

Your email address will not be published. Required fields are marked *