If you think all coconut coir is the same, get ready for a surprise. There are various types of coir, and not all are created equal. Here’s what you need to know if you're using coconut coir as a growing medium.
1. Quality of Raw Coir
Don’t assume that buying a bag of coir means you're getting the same quality every time. Coir comes in all sorts of forms, often mixed with husk, shells, fibers, and even branches. The worst part? Young, green coconuts get thrown in the mix. These contain high levels of tannins and take a long time to properly process.
If the price seems suspiciously cheap, it might be because the coir is stuffed with extra fibers that make it seem heavier than it actually is. The highest quality coir is finely processed, with almost 0% fibers—this is the premium stuff worth the money.
2. Types of Coir Products
Ever opened a big bag of coir that felt super light? That’s probably because it was packed with tons of fibers and fillers. On the flip side, there are smaller bags that feel heavy but are filled with more usable coir.
The ideal moisture content after processing should be capped at 60%. Any more than that and you risk water leaking everywhere, or the weight of the bag becoming an issue during storage. The best type for seedling nurseries has almost 0% fiber content, making it super easy to mix or use directly in trays or pots. Naturally, this kind costs the most!
Another option is using inert coir as a growing medium. You can add it to containers, grow bags, or shape it into slabs for growing.
3. Coir Quality Indicators
All coir needs to be properly processed to remove tannins and lignin, which is a complex and costly process. To measure quality, you should refer to the EC (electrical conductivity) scale:
+EC ~ 0.5: You can start using it, but if you're only using this type of coir, plant roots won’t grow well. Young plants will likely get yellow leaves, grow slowly, and have poor fruit yields later on. You’ll end up needing to apply extra fertilizer to make up for it, and even then, your plants may suffer.
+EC ~ 0.2: This is a decent level for growing, though the roots can still be somewhat affected.
+EC ~ 0.1 or lower: This is the top-quality coir on the market. It's super versatile and great for different types of agricultural use. Naturally, it’s also the most expensive.
4. Important Considerations
One issue people often overlook is salt contamination in coir. Some suppliers just toss the coir bags into rivers to "wash" them and then fish them out later. The problem? These rivers can be full of salt, especially in coastal areas. It’s crucial to know where your coir comes from.
Lignin, a tough compound found in coir, only breaks down in highly alkaline environments over a long period. Most processors use lime, but the coir naturally holds onto water, making it hard to rinse properly. If the EC stays high, you’ve got a problem.
Also, inconsistent raw materials can cause EC levels to fluctuate wildly, making the coir less reliable as a growing medium. If you don’t have the experience to handle this, the coir will be of poor quality, and you won’t get the results you want.
Rainy season? Even trickier. Weather can mess with processing, storage, and overall product quality.
5. How to Use Coir Properly
Let’s clear up a common misconception: “clean soil” that’s actually full of coir isn’t really soil. Don’t be fooled by the label. Coir, once processed, contains no nutrients. It’s just a growing medium to anchor plant roots, so all nutrients need to be provided externally.
To use coir effectively, you need to mix in the right components (as I mentioned in post #1). Since coir is just a medium, it lacks the natural microorganisms that help plants absorb organic fertilizers. You’ll need to introduce beneficial microbes (see post #22) to make the coir work for your plants.
6. A Few Extra Tips
At first, coir drains water super fast because it's so light and airy, which can mean more frequent watering. To avoid this, mix it with materials that help retain moisture.
As plants grow and their roots fill out, coir can become compacted, reducing drainage. The surface may look dry while the bottom is waterlogged, so use containers with good drainage.
Another issue is nutrient runoff. In large-scale operations, coir can cause fertilizer and water to wash out quickly, often leaving behind a green layer of algae. Over time, this leads to fertilizer waste and environmental pollution. You’ll notice it in rivers, lakes, or streams near farms using coir-based growing systems.
For this reason, I’ve always stressed the importance of maintaining a healthy, clean garden. Don’t just jump on the coir bandwagon because it’s trendy. Use it only if you truly understand how to manage it properly.
Finally, after you've finished a growing cycle, dealing with used coir can be a headache. I’ll talk more about that in a future post, but trust me, if you’re not careful, it can be more trouble than it’s worth.
As a final note, the coir we produce is top-tier quality. Our product has nearly 0% fiber content, perfect moisture levels, and an EC of ~0.1. If you don’t understand the details of this process, you’ll end up wasting money and struggling to produce a good yield. So, ta