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Is Coir the Perfect Growing Medium?

You may know it as coco peat, but we call it coir. It avoids confusing coco peat as a kind of peat - which it most certainly isn’t. It’s actually far superior to peat, more versatile and eco-friendly.  

Coir (pronounced COY-uh) is fast becoming a standout choice of growing media/substrates. It’s an organic soilless medium derived from coconut husks and is a great choice for indoor and outdoor growing – though particularly prized in controlled greenhouse climates. 

Growing media set the foundation of your plant's life, creating the environment for roots to establish themselves and flourish. The substrate you use needs to strike a balance between aeration and water retention - crucial factors for plant health and growth. We think coir is the best in its class. But you’ll still need a professional to help you get the balance right. Coir is not a one-size-fits-all solution.

How it’s Made

1. Harvesting and softening

After the coconut harvest, the husks undergo a softening process in either a freshwater or saltwater bath. However, sodium can be detrimental to plant health. Saltwater-treated coir will have higher sodium levels and so will coir that is harvested near the ocean. To ensure quality, freshwater-treated coir is the better choice. Vegtech Netafim’s coir is thoroughly washed in fresh water for these purposes.

2. Extraction and drying

Next up is extracting the coir from the husk. Once extracted, it is laid out to dry for up to a year. The longer the coir matures, the higher its quality and nutrient-holding capacity. Matured coir should be washed again to further remove dust, salt, and impurities. Dust can account for up to a third of the weight of the coir you’re buying, with unwashed coir offering far less substrate than you paid for.

3. Processing and packaging

Finally, the coir is compressed into compact bundles or bales. Depending on the end use, the bales contain different quantities of piths, fibres and chips. Each combination offers different aeration and water retention capacity and each crop will require its own unique balance.

The Benefits of Growing in Coir

Neutral to Slightly Acidic pH

Successful yields depend on the pH level of the growing medium. Coir typically has a pH level of neutral to slightly acidic, aligning perfectly with the requirements of most plants. This pH balance aids in nutrient absorption, ensuring easy access to important minerals. Some plants, like blueberries, require a more acidic environment, and Vegtech Netafim can ensure that the coir is treated to provide it. Also, as a certified Priva partner, we’ll help you leverage their tech to adjust pH levels as you go, ensuring the ideal condition for each plant.  

Low Electrical Conductivity (EC)

EC levels, indicating salt content, are paramount for healthy growth. Our coir has low EC levels, because, as mentioned, it’s been thoroughly fresh-water rinsed in the manufacturing process. Low EC prevents potential harm to plant roots, a common issue when salt content is high. Using advanced fertigation methods, Vegtech Netafim ensures that the already low EC level of your coir is maintained, providing an ideal environment for root development and plant health.

Superior Aeration Ability

One of coir’s standout features is its generally loose structure. This enhances soil aeration and oxygen penetration in the roots - crucial for root respiration and nutrient uptake. Some crops need less aeration than others, so we customise the balance of piths, fibres and chips to ensure that the aeration is perfectly matched to each need. We can further optimise aeration needs with carefully selected grow bags and troughs that assist in providing the right balance of air and moisture per crop and stage.

Excellent Water Retention and Drainage

Coir can retain 8-9 times its weight in water while providing excellent drainage. It naturally balances the water levels throughout the medium, with our precision irrigation doing the rest. Even on its own, coir helps to promote irrigation to maintain the right water levels. This means that plants have access to moisture as needed, while avoiding waterlogging. We still recommend that growers opt for precision irrigation to complement coir’s unique applications. 

Customisable Nutrient Management

Compared to soil or sawdust, coir is an inert growing medium that allows for complete control over the plant’s nutrient management. This perfectly aligns with Vegtech Netafim's advanced fertigation methods, offering precise nutrient delivery for specific growth stages and needs. 

Disease Resistant

Coir is sterile and naturally resists soil-borne diseases, significantly reducing the need for chemicals. This resistance is bolstered by the presence of beneficial microbes and natural substances, leading to healthier plants and reducing the environmental impact of chemical use.

Highly Versatile

Coir can be customised based on the environment and plant-specific requirements. As greenhouse experts, Vegtech Netafim can tailor the composition of the growing medium to match the unique water retention, EC, pH and drainage needs of each crop. This customisation ensures that each crop receives the ideal growing conditions, maximising yield and quality. 


As a natural by-product of the coconut industry, coir is an eco-conscious choice. Being 100% biodegradable, it contributes positively to the ecosystem by decomposing and adding organic matter to the soil. 

Sustainability and Smart Long-Term Investment

Coir’s high lignin and cellulose content ensures slow degradation, enhancing its sustainability and longevity. Coir is also a cost-effective substrate as it can be reused for multiple growing seasons, lasting in quality for 2 years. It’s no wonder that it’s a favoured choice. 

Outperforms Sawdust

Compared to other growing media like sawdust, coir emerges as superior. Sawdust can negatively impact fertiliser efficiency and plant growth due to its high carbon content and potential for nutrient lock-up. In contrast, our coir provides a neutral growing environment, free from these, and other, disadvantages.

Ready to know (and grow) more?

Understanding the pivotal role of substrates, we ensure that our coir is thoroughly cleaned and of the highest quality. We’ll also customise your coir and ensure that you have the correct quantity, based on its expansion rate in water, to produce your ideal crop volumes. 

At Vegtech Netafim, we’re committed to sustainable and innovative agricultural solutions, empowering our clients with the knowledge and skills to maximise coir’s potential. We also offer comprehensive greenhouse farming support. To find the right mix of coir for your needs, give us a call on +27 21 987 6980 or drop an email to