I heard that fish fertilizer is good for my container plants. So I decided to do some research if I can buy some fish from the market and use that as fertilizer in my garden.

You can use dead fish as fertilizer because they contain nitrogen and traces of various minerals. You can cut up the pieces of fish and add them to the soil. Or you can crush them up in a blender and use the mixture as fish fertilizer.

Whether you’re new to gardening or a seasoned pro, dead fish can make a great fertilizer. Before you start using it that way, consider how to prepare it to give your plants the optimal conditions. Keep reading to learn more about using dead fish as fertilizer.

Should you make your own fish fertilizer?

If you buy fish for your meals and have some leftover, you can use that. The best parts of the fish to use are parts that you can’t eat, such as the head.

You can also buy fish just for making fertilizer out of them and not for your consumption. You can use fish like salmon, tuna, or tilapia for your garden.

It’s important to cut up the fish well enough before you mix it in the soil. The smaller the pieces, the faster the nutrients will mix into the soil.

The other option is to use fish fertilizer that comes ready to use in the garden. You can get fish fertilizer made from a variety of fish species.

Buying ready-made fish fertilizer can be a great option if you don’t want to deal with cutting and preparing dead fish.

How to prepare dead fish fertilizer

If you bought fish for your consumption, you’ll have some scraps left. These could be parts of the fish you cleaned before cooking and scraps leftover after the meals.

Collect the scraps of fish

Make sure the scraps are clean and free from any dirt. You can wash the raw fish parts like the head with water.

You can chop up the fish parts so they are made into tiny pieces. This will help you blend them up later.

Put all the parts in a container you keep just for the purpose of creating fish fertilizer. Put any scraps leftover from your meals into the container.

It does not matter if the fish parts are spoiled and you can add them to the container as well. But this is entirely your choice. Spoiled fish will have a strong smell that you may not prefer in your garden.

Prepare a mixture from the scraps

You need to add the fish parts you collected in a hand grinder or stick blender. Turn it on and make sure the pieces are ground up well.

I would suggest keeping a hand grinder or stick blender only for making your fish fertilizer. You don’t want to use the same blender you use for preparing your food.

It will be hard to clean this blender and get rid of all the smell. Especially if you’re going to use spoiled fish.

Once you finish grinding, you can store the stick blender with your gardening supplies. And if you only use it for fish, you won’t have to clean it as deeply.

Prepare emulsion from the scraps

If you don’t want to grind the fish or don’t have the right tools, you can prepare a fish emulsion. This is fish in liquid form that you can combine with water and add as fertilizer to the garden.

One of the benefits of fish emulsion is that it has high nitrogen levels, which can help your plants. However, it can burn your plants if your soil already has plenty of nitrogen.

You can make a big batch of the fish emulsion by using the below steps.

  1. Grab a five-quart bucket and put your fish scraps in.
  2. Layer the scraps with leaves until the bucket is a little over half-way full.
  3. Add another layer of fish scraps and fill the bucket with water.
  4. Close the lid on the bucket, then store it but check on it each day.
  5. After gasses begin forming, stir the emulsion each week.
  6. Once a month has passed, strain the leaves and fish so that you have the liquid.

You can combine a gallon of water with five ounces of the emulsion. Then you can use it to water your plants about twice per week.

How to use the dead fish fertilizer

Before you put the fish in the soil, though, check the nitrogen levels. You can use a soil test or look for signs of low nitrogen levels, like pale green leaves. If the nitrogen levels are high, don’t use too much fish, but you can use more if your soil is low in nitrogen.

If you’re using the fish mixture, you can mix it directly into the soil. Make sure to mix it well so it goes deep into the soil. You need to do this whether your plants are in the garden or in a container. This will also help prevent the plants from smelling too much of fish.

How often should I use fish fertilizer?

If you’re using dead fish pieces, you just need to use them a few times. The first time you can use the pieces or mixture is when preparing the soil for the garden or container.

Mix the dead fish pieces or mixture into the soil with your hands or a rake. Make sure it gets mixed well into the soil.

You can then use the fish pieces or mixture 1-2 times during the growing season in the same way. Mix the pieces or the mixture well into the soil but make sure not to disturb the plant’s roots.

If you’re using fish emulsion you can create a diluted mixture an ounce fish emulsion in 1 gallon of water. Then apply it to the soil twice per week to get good results.

Is using dead fish good for plants?

Native Americans had been burying dead fish under the plants for a long time. They understood the benefits that it provided to the plant growth.

The dead fish is broken down slowly by the organisms in the soil that convert it into nutrients and organic matter. This is beneficial for the plant’s roots that absorb these nutrients and provide them to the plant.

The fish material provides nutrients that are rich in nitrogen. It also contains some amount of potassium, phosphorus, and calcium that is beneficial for the plants.

Can I put dead fish in compost?

Fish is an organic matter that decomposes well. So it might seem logical to add it to your compost pile.

The problem is that the decomposing fish has a sharp smell that will attract rodents, cats, dogs, and other animals to your compost pile. The smell will also be a nuisance if the compost pile is near your house or your neighbors.

One solution to this problem is to compost the fish under the soil. You can create a compost pit and put the fish inside it. Let it decompose underground for several months and you can later use the material as compost.

Use store-bought fish fertilizer

If you want to avoid the process of making fish fertilizer, you can buy some at the store. Not only can this save you time, but you can find odor-free fish fertilizers. Then, you won’t have to worry about cutting up old fish, and you can save yourself from the smell.

You’ll also be able to find the right amount of fertilizer that you need. And if you don’t like eating fish, you won’t have to waste the money on getting fish just to use it as fertilizer.

Special Considerations

Before you use dead fish as fertilizer, consider a few things. For one, some fish can have a strong smell. Even if they don’t smell strong now, the fish can develop a smell as it stays in your garden.

As that happens, your garden may start to attract wild animals. So be sure you have some form of protection, like a fence, to keep animals away.

You should also consider the source of the fish. While some pieces of fish are fine to put in a garden, some fish may have high concentrations of mercury or other toxic metals. If you use too much of the fish, you may unwittingly harm your plants.

Final Thoughts

Dead fish is a great option for fertilizer for many gardens. Whether you make it yourself or buy it from the store, you can use it to give your plants the nutrients they need.

However, make sure your soil can withstand the high levels of nitrogen and that the fish don’t have too many toxins.