Is Osmocote Biodegradable?

  • By: greenorb
  • Date: May 7, 2022
  • Time to read: 5 min.

Do you want to use Osmocote fertilizer but are worried about its biodegradability?

Osmocote fertilizer comes in coated beads that enable a controlled release of nutrients to your plants. 

It makes it easy to feed plants with a precise amount of fertilizer over a given time, preventing sensitive plants from burning. 

However, there are a lot of questions about whether Osmocote is good for the environment. Let’s talk about that. 

Is Osmocote Safe For the Environment?

Osmocote is a great fertilizer. It is all about controlled delivery, timed-release, enhanced plant growth, plant health, and the results that you could get. notes that Osmocote fertilizer has been around for a long time and is one of the most efficient fertilizers you can use to sustain the nutritional value of your soil. 

However, we cannot ignore that it is completely inorganic. It also claims to offer all the benefits of organic fertilizers. 

The reality is that Osmocote only offers a constant release of fertilizer over a safe time, but it’s inorganic at the end of the day.  

The benefit of inorganic fertilizers is that they are in a usable state. All organic fertilizers must first become inorganic to be absorbed by plants. 

Unlike most organic fertilizers, Osmocote is a perfect blend of potassium, phosphorus, and nitrogen, all of which are safely released over a longer period. 

The coating is usually soybean or sometimes microplastic beads.

When we consider the safety of Osmocote, we look at two things – firstly, the safety of all fertilizers, and secondly, what Osmocote is made of. According to UNEP, pollution due to fertilizers has to do with their “excessive and inefficient use.” 

There’s no fertilizer (not even Osmocote) that is 100% safe for the environment, especially when excessively used – rainwater can wash it away into our water streams. 

NOTE: Regarding the processing of Osmocote, soybean coating is safe for the environment, but the microplastic coating isn’t

Does Osmocote Decompose?

Yes, Osmocote is water-soluble and degrades over time. 

Remember, moisture is a solvent that dissolves fertilizers, so it hastens the leaching of Osmocote into the soil. 

Here’s how Osmocote fertilizer works. You get nutrient pellets that you can apply to your plants. 

These pellets are coated with semipermeable soybean, alky, or linseed oil-type resin that allows water to go through them and dissolve the encapsulated nutrients. 

The idea behind the use of semipermeable pellets is to allow the controlled dissolution of the nutrients over time. 

Although the contents of the pellets easily decompose when subjected to a moisturized environment, the rate of decomposition depends on ambient temperature, the size of the pellets, and the thickness of their coating. 

The pellets are not the fertilizer but only a medium for holding nutrients as they dissolve in a controlled manner. 

If they are made of linseed oil or soybean instead of microplastic, they will decompose after a few months. 

Does Osmocote Use Plastic?

Osmocote sometimes uses plastic, but it depends on the manufacturer. 

For years now, Osmocote has been among the top Polymer-Coated Controlled-Release Fertilizers (PCRF), meaning it features a plastic coating on the pellets. 

This plastic coating is made of polymer resin, a soft liquid plastic that creates a semipermeable membrane between the nutrients and solvent factors such as water, soil, etc. 

Since plastics are naturally non-biodegradable, we don’t expect synthetic resins to be biodegradable. 

Unfortunately, the polymeric resin coating on Osmocote doesn’t biodegrade and is usually recycled carefully to prevent the release of toxins into the environment.

Due to the environmental problem of plastics, some manufacturers consider alternative materials such as soybean and linseed oil for coating Osmocote. 

Unlike polymeric resin, soybean and linseed oil are organic and easily decompose. 

Can Osmocote Be Used In Organic Gardens?

One of the major differences between traditional gardens and organic gardens is that the latter usually don’t rely on artificial fertilizers and agricultural chemicals. 

Most organic gardeners encourage using natural supplements such as animal manure to boost plant health, so they might not use Osmocote. 

If you are an organic gardener, it’s advisable to avoid Osmocote and other artificial fertilizers and opt for concentrated compost instead. 

All in all, Osmocote is made to serve plants with essential nutrients such as phosphorus, zinc, etc. Each granule contains almost all these nutrients. 

So, even if you are an organic gardener, you may consider preparing a separate garden where you can use this fertilizer. 

Many people use Osmocote with house plants and edible garden plants such as vegetables, fruits, etc. 

However, you can use it on any other plants that you feel lack the nutrients that this fertilizer offers. 

Pros and Cons of Osmocote

Like any other product, Osmocote has its benefits and drawbacks as well. 


  • Steps up your gardening – If you want to give your plants the right amount of essential nutrients, Osmocote is the best option.
  • Works with composting – Yes, you can put Osmocote in your compost pile. The reason for mixing the two is that you want clean water. Composting needs too much water, which causes too much nitrogen to go into the ground. Nitrogen usually ruins water quality. 
  • Reduces fertilizer pollution – since Osmocote is all about the controlled release of plant nutrients, it reduces the amount of fertilizer being washed away into the rivers when it rains. 


Apart from being pricier than ordinary fertilizers, the other problem with Osmocote is that most manufacturers use plastics for coating granules. As the world is fighting the plastics menace, we all need to adopt environmentally friendly products

Final Thoughts

Using Osmocote in your garden is a great idea. The fertilizer adds essential nutrients to the areas where there are none, and it features efficient capsule technology to ensure controlled usage. 

The problem with Osmocote is that while we are fighting hard to attain a green environment, some manufacturers still use the plastic coating on the granules.

Plastic shells are non-biodegradable and may remain in your plant pots years after nutrients are depleted. 

So, always ensure you’re getting eco-friendly options with soybean or linseed oil-type coatings. 

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