How to Dispose of Old Fertilizer Safely: Everything You Need to Know

How to dispose of old fertilizer safely

Fertilizers contain chemicals that may be good for the plants but are actually quite toxic. These chemicals are considered hazardous waste and should be disposed of properly.

Here is your step-by-step guide on how to dispose of old fertilizer safely:

What You Need to Know About Fertilizers

Everybody knows what fertilizers do. They make plants healthier and bloom beautifully.

But what is it made of?

There are three important components of a fertilizer:

  • Nitrogen
  • Phosphorous
  • Potassium

These three have different roles in ensuring that you have a healthy and beautiful garden. 


Nitrogen will make sure that the plants will have a leafy growth and would make the colors of the plants pop. It makes plants really green and the flowers really bright. 

Phosphorus, on the other hand, ensures strong root development. Potassium encourages efficient growth. 

Check the label:

The fertilizer container will tell you how much NPK (nitrogen, phosphorus and potassium) the whole pack contains. The label will feature three numbers of the NPK. 

You will know how much NPK you need when you test your soil. 

They also come with secondary components like sulfur, magnesium, and calcium.

Bags of fertilizer stacked up in front of tree

It comes in two forms:

You can get a dry or liquid fertilizer. Dry fertilizers are integrated into the soil and will begin releasing nutrients as soon as the area is watered. 

There are fast-release and slow-release types of dry fertilizers. The latter will provide the plants with a slow nutritional diet over several months. 


The liquid fertilizer comes in concentrated substances that need to be diluted in water before you apply them to the plants. 

This is a better fertilizer when you are taking care of potted plants. For ground plants, this can be used as a supplement fertilizer.

Whatever form it takes:

It’s clear that fertilizers contain chemicals. Many of them also have added pesticides and herbicides in them so that they don’t just keep the plants healthy, they will also prevent pests from destroying the plants. 

They can be poisonous when accidentally ingested by people or plants.  

Why You Need to Dispose of Fertilizers Properly

Nitrogen used in fertilizers comes in the form of ammonium nitrate, which is a chemical compound that could explode when there is heat and shock. 

When present at high levels in people, the nitrates will lower the red blood cells’ capacity to deliver oxygen to the rest of the body. 

Remember this:

When you are handling fertilizers, you need to wear gloves. If you can wear goggles and a mask, that would be good too. 

If fertilizer comes into contact with your skin, you may experience a burning sensation and it may become red. In somes cases, it could be itchy. Or you could also have a burning sensation on your nose, in your eyes, and even the throat.

Person itching arm

These could be symptoms for fertilizer poisoning.

To be clear

This doesn’t happen to everybody. And just because you didn’t experience the above-mentioned symptoms doesn’t mean that fertilizers are not dangerous. 

Now, if you inadvertently ingest fertilizers, you may experience dizziness and fainting. You may also have low blood pressure and may even experience a seizure.

With that said…

What are you going to do about it?

You have to properly dispose of fertilizers. You can’t just throw away fertilizer in the bin like it’s regular waste. It’s not!

There are so many adverse effects to not appropriately disposing of fertilizers. 

Picture this:

It rains really hard and your unused fertilizer has been carried off by runoff water. It reaches the waterways. 

Too much nitrogen in water could reduce the amount of oxygen. Then, there won’t be much oxygen left for all the water inhabitants. 


When there is an excess of nitrogen, it could add to the release of greenhouse gases that pollute the air. 

That’s why you should only use the right amount of fertilizer in your plants. Then, if you have unused fertilizer, you could give it to people who need it or you should dispose of it properly. 

Guide on How to Dispose of Old Fertilizer Safely

Now that you know fertilizer could be dangerous, make sure you properly throw them away. 

Here are the steps you could follow to make sure that fertilizer won’t further damage the planet, and more importantly, won’t threaten people’s health.

Fertilizer in storage shed

1. Store fertilizer properly

While you are still figuring out how to dispose of the fertilizer, make sure that it is stored properly. First, it should be stored in a cool and dry place. 

Second, it should be somewhere that children and pets cannot reach. You don’t want them accidentally moving the fertilizer, or worse, accidentally ingesting it. 

If possible

Keep the fertilizer in its original container. Don’t mix different types of fertilizers, by the way. You don’t know the chemical reaction when you do this. 

2. Give them to somebody

This should be the first step of actually disposing of old fertilizer. So that you won’t waste your money, you should give it away to somebody who needs it–family members or friends who are also into gardening. 

3. Contact local recycling facility

Most recycling facilities take hazardous waste for proper waste disposal. However, not all of them will accept fertilizers and similar products like pesticides and herbicides. 

If they do accept them, then great. If not, ask them which facilities accept fertilizers. They should have that information. 

4. Call local garden supplies store

If you have no luck with a recycling facility, check your local garden store. Ask them if they accept unused or old fertilizers. 

5. Package properly and then dispose

Now, if you have no luck looking for places that will accept your fertilizer, then you have to do it yourself. 

The most important thing is that you package the old fertilizer properly so that there is no chance of the contents spilling over the other garbage. 

What you need:

  • Thick plastic bags (trash bags or large zip-top bags)
  • Newspaper or scratch papers
  • Adhesive tape
  • Gloves, goggles, and mask

What you have to do:

a. Wear your protective gear

Put on your gloves, goggles and mask. You want to protect yourself from possibly having contact with the fertilizer or even ingesting its fumes. 

Person with plant pot gardening

b. Keep the fertilizer in its original container

For liquid fertilizer, make sure you wrap the lid with adhesive tape to ensure that contents will not spill when thrown away. For the dry fertilizer, roll the top of the container down and then seal it extensively with adhesive tape. 

c. Wrap it in newspaper

Spread out at least three layers of newspaper pages. Wrap the fertilizer with it and put the adhesive tape around it. Be generous with the adhesive tape to make sure there will be no spillage. 

With the liquid fertilizer, you have to be even more generous with the newspaper because you want to make sure that if the contents leak, the newspaper will be thick enough to soak everything up. 

d. Seal them in the plastic bag

Put the fertilizer inside the plastic bag and close it–tie it or zip it, depending on what type of bag you are using. You can double or triple pack the item, too, just to be completely sure. 

e. You can now dispose of the item

It would be really helpful if you can also call the local garbage collection company and inform them that you have fertilizer among your waste products. 

Person using fertilizer on plants


Fertilizer is good for the plants. You need them to make sure that your plants grow beautiful and healthy. However, fertilizers don’t have the same effect on humans. 

No, you don’t eat fertilizers. However, there is a chance that you might inadvertently ingest them. That’s not good! Fertilizers can be poisonous and could endanger a person’s health. What more, it adds to pollution in the water and in the air. 

This is why it’s necessary to throw fertilizer properly. You need to find better ways on how to dispose of old fertilizer safely.

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