What Is Coco Coir? 7 Reasons We Love It Plus a Few Dislikes

What is coco coir, and why do we love using it so much?  Coco coir comes from processing the thick brown pith surrounding the hard coconut we see in the store.  It's a waste product from harvesting coconuts.

The coconut industry has found or made a product out of waste. Although, making coco coir from coconut waste is not an easy or straightforward process.

What is Coco Coir? A Modern Coco Coir Producer

That video is one of the best we could find because it shows all of the processes (except one) separating the fiber, grinding the pith, composting the pith, and packaging the products for export. 

We'll discuss this process more later on in the article.

What is Coco Coir, and How Is It Made?

The idea of using coco coir in gardening and growing crops isn't new. In fact, it was being used in the 1800s, but because of its low fertility (can you say none) and high salt content, it was not widely exported.

Fast forward to today, with the advent of better liquid fertilizers and amendments, it has been rediscovered as an organic, environmentally sustainable soil substitute.

If you've handled a coconut in the grocery store, you've only seen the harvestable portion of the drupe.

What's a drupe? I wasn't sure either until I read that article.

what is coco coir and how is it made

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You can see she is eating the white coconut meat covered in the hard, fibrous covering that we see in the store. What we see in the store is called the drupe.

But coconuts have a thick layer of pith (as you can see, a couple inches thick) around the drupe.

The pith is covered by smooth skin, green when not ripe, becoming brown as it matures when it is ready to fall from the tree.

The coco coir fiber used in mats and planter liners and coco coir peat we use as a soil replacement comes from this thick pith layer.

This pith needs to be softened by composting before being processed for coir.

Composting loosens the fibers in the pith making it easier pull apart and separate. 

Long fibers are separated from the smaller and finer fibers and are used to make many common household objects.

coco coir comes from coconut pith

Composting Coco Coir Husks

Often this is done in brackish lagoon water to speed up decomposing and loosening of coconut pith fibers. Coconut fibers are tough, so they may need to soak for months.

Soaking in brackish water can add unwanted salt to the finished product. But luckily, coconuts are grown in the tropicals, so before they are processed, they are spread out so rain can wash off much of the salt.

Many of the larger coir producers allow the coconut husks to compost in piles on land instead of lagoons to reduce salt content.

Popularity Demands Change for the Coconut Coir Industry

As coco coir becomes more popular and in higher demand, the industry has added mechanical ingenuity to drastically reduce the composting period. Increasing strict product requirements from buyers has also forced coir producers to reduce salt and provide better working conditions.

Hopefully, the industry will make sure even small producers improve safety, work conditions, and income. 

What is Coco Coir? Video 2 - "Old School" Small Coco Coir Producer

Note: In a previous life I often did environment and safety compliance work. While researching this article I've never seen so many chains, gears, high speed blades, and pinch points without machine guards in place. Scary.

Creating Coco Coir and Fiber

As shown in the video above, the next step is to separate the long coconut fiber from the smaller material that will become our microgreen soil. The long fibers are removed by steel combs. The remaining material is chopped, cut, and ground into a fine material similar to peat moss.

One of the things we like about coco coir is that it still contains some of the more course pith and chopped fibers. The different textures allow the coir to drain better than peat moss. It also leaves more pore space for air to exist and roots to grow.

Packaging Coco Coir Fiber and Coco Coir Peat

Many products we commonly use are made from the long coco coir fibers. These are shoved into a compactor and baled for easier transport. You can see that process at the 1:05 mark in the first video.

The coco coir we use is usually composted and washed before it is dried and placed in a machine that compacts the small particles into bricks and blocks. To see this in action, go to the 2:16 mark in the first video.

How Much Coco Coir is in a Brick or Block

The compacted nature of the coco coir bricks and blocks makes the export of coco coir economically possible. I guess the same can be said of peat moss with the compacted bales.

Our understanding is that the industry-standard compaction ratio of coco coir bricks and blocks is 5:1 by volume.

So our Coco Bliss Coconut Coir brick measuring 8" by 4" by 2" (64 cubic inches or 1.1 quarts) will expand when water is added to 5.5 quarts. 

what is coco coir brick

Note: We will test this in an upcoming video article on hydrating coco coir blocks. Then comparing the cost to bagged soil. 

I think the ratio will be much higher, more like 8:1. But this is why Home Microgreens tests internet dogma.

We want to know. 

Pros & Cons of Using Coco Coir for Microgreens

It may be strange to list the pros and cons of using coco coir in an article titled What is Coco Coir. But I want to address why we recommend using coco coir over other potting media. We also have some reservations about using it as well. 

Pros and Cons of Using Coco Coir

Pros:

  • Renewable product 
  • Easier to ship larger quantities 
  • It wets well - goes from dry to moist quickly 
  • Wicks water well - easier to bottom water  
  • Drains well, less chance to overwater
  • Chemically neutral
  • It grows microgreens the best! It works.

Cons:

  • Worker safety
  • Low wages and working conditions  
  • Not sustainable
  • No nutrients 
  • Hydrating bricks correctly 

Cons of Using Coco Coir

First, let's touch on the social aspect. 

Social: Worker Safety

Without any first-hand knowledge (I know, this is what I hate about the internet), I expect that working conditions in the coir producing regions aren't up to the standards that we expect in North America. 

In the second video, and in the tens of others I watched, many people are working in loose garments around chains and gears that don't have mechanical guards. Most people aren't wearing dust masks around the machines. Small fibrous coir strands can't be good for the lungs.

Worker safety is essential. Some would say too much emphasis is placed on safety here in the States. That is until they get hurt, then they lawyer up. But we want everyone to go home in one piece after work. 

Social: Pay & Working Conditions

Again, I haven't seen any pay stubs, but I'd expect that the pay is low and the hours are long. 

But, I'm also sure everyone needs to eat and pay their bills. So I'm not judging the workers' choice on where to work.

More to the point, the owners' decision to not provide better working conditions and compensation. The producers need to stand up to the buyer and demand more money.

Be sure that the companies buying the finished product are making more money per unit than those making the coir. This upside-down economy, the same we see between grocery chains and farmers/producers, has to change.

Steps off the soapbox.

A while back, I saw a video that really went into the coir industry's sustainability and workers' conditions. I wanted to put it in this article but couldn't find it when I needed it. It showed the hardships of the workers to prove the point above. Hopefully, I'll come across it again.

Environment: Not Sustainable

Before you lambaste me, let me say that coco coir is definitely a RENEWABLE resource. We can produce more of it without shortage. 

But is coconut coir a sustainable product when we transport it halfway across the globe? According to all of the definitions I've read, this is not a sustainable practice

I wonder if we aren't depleting local natural resources by removing so much organic matter from the coconut groves.

Usage: No nutrients

Pure coco coir has no inherent nutrients available for seedlings or plants to use. At least, this point is not dogma as we have evidence that microgreens grown in pure coco coir do not grow as quick or as large as those grown in potting mixes.

Dark Opal Basil after 19-days

At Day 19 you can see that the basil in the nutrient poor coconut coir is falling behind the mixes. Left to right, pure coconut coir, Coco Loco Mix, and Happy Frog (peat-based) Mix.

Coco coir by itself can't sustain growth once the energy in the seed has been used up. However, adding a good liquid fertilizer, such as Ocean Solution, to pure coconut coir should add enough nutrients to grow awesome microgreens.

We will test that hypothesis using coconut coir with Ocean Solution in a future article. It worked wonders growing microgreens on Terrafibre™ hemp matting, so it should work with coco coir too.

Peat moss also does not have much if any, natural nutrients. Pure peat moss is in the same nutrient-poor boat as coir.

Usage: Hydrating Coco Coir Bricks

We are very particular about the amount of moisture in the soil we use. If you've read any of our planting articles, you've seen that we only wet the upper surface of the soil.

Excess moisture can only cause problems during germination. 

Coco coir blocks are brick hard and extremely dry. The only way to make these coir bricks useable is to soak the brick in water. This process isn't an exact science - though we will try to make it so in a future article - and the coir contains a lot of moisture.

It's a semi-controllable process, so you can get away with planting in a new batch of coir. But when it comes to storing the extra, here's where the problems occur. 

We've ruined a lot of coir trying to store the extra. It's usually too wet, and when you cover it, mold starts to grow. You can add air holes to the container or leave the cover off for a while to let it dry out.

But this can cause fungus gnats to appear, or you forget to mix it up, and it starts to mold toward the bottom of the storage container. 

We don't like to leave any soil, not growing plants, open to the air. Covered is better.

Pros of Using Coco Coir

There are a lot of things we love about coconut coir. Maybe not using 100% coconut coir, but as an ingredient in a potting mix.

Environment: Coir is Renewable

As mentioned, we don't believe coir is a sustainable product. Still, it is renewable, and it makes use of a waste product. We can plant more coconut groves with careful planning and produce as much coir as we need.

Canada is where most of the peat moss used in horticulture is mined.

We realize that the Canadian peat moss associations report that they harvest peat moss responsibly. And that peat moss is forming faster than it's being mined, but as a geologist, I know the volume of peat moss mined is more than is being created.

Currently, we believe in renewable over the sustainability of transporting coir. Plus, we have peat - more on this below.  But, our views may change in the future.

Transport: Coconut Coir Bricks and Blocks

Coconut coir can be compacted very tightly, making it easier to transport long distances. Like these 11-pound blocks. Coco coir bricks are also made usually around 1.4-pounds.

We found the ratio of 5:1 in our research. Peat moss is reported to be a bit more than 2:1, maybe 2.5:1.

We will test this in a later article. Still, suppose you think about how much coir can be transported in a cargo ship and expand that by five times. In that case, you can understand why coconut coir can be transported economically.

Usage: Wetting Properties

We consider wetting coconut coir different than hydrating coir. The coir we use in our potting mix or in other loose fill bags (not bricks) has already been expanded from blocks. In the bags, the coir in the potting mix is dry or slightly moist.

You can't squeeze any water out of the potting mix.

But when you mist or spray water on the coir, it immediately absorbs the water. Peat moss does not; it's hydrophobic and is difficult to wet. You can see this in the photos and videos in this article.

The quick wetting of coir or a coir-based potting mix makes it easier to control the moisture during seeding and watering as the microgreens grow. 

If coir dries out, it can be quickly re-wetted. While water sits on top of dry peat moss.

Usage: Wicking Properties

As quickly as coconut coir absorbs water, it also drains excess water very well. It's hard to over-water a coir-based potting mix if it's given a place to drain.

Now, you can over-water a tray of microgreens if you allow it to sit in water. Still, if the tray is elevated, the coir will self-regulate the moisture better than peat.

Part of this is because of the fibrous nature of coconut coir. 

It doesn't compact as peat moss does, and water can run down the coir's longer fibers instead of being collected in the leaf-like texture of peat moss.

However, coconut coir still has moisture in the fibers itself and where fibers criss-cross each other forming pore space. Coir also retains air in these pore spaces making it an excellent growing media.

Usage: Draining Properties

As well as coconut coir wicks up water, it also drains well. It's tough to overwater most microgreens when using coco coir-based potting mixes. 

As long as the tray isn't resting in water and there is a place for excess water to drain, coco coir will not retain too much water.

There are exceptions; Swiss chard, beets, and amaranth are sensitive to moisture even in coco coir. But excess water retention is worst with peat moss or other potting mixes.

We believe it is the larger pore spaces and longer pieces of coir that help water drain from coir-based potting mixes. 

Potting mixes drain better than pure coir because they have more pore space and avenues for water to move within the potting mix.

Usage: Neutral Properties

The chemical properties of coconut coir will not affect the ability of any plant to grow.  Chemical growing parameters can be easily controlled by the water and what you add to the water. 

Usage: It Works - With Additives

Of all the potting mix trials we have run, coconut coir potting mixes have grown microgreens equally or better than others.

When push comes to shove, all we want is results.

Red Garnet Mustard Microgreens 14-days after planting

That is what coconut coir-based potting mixes will give you is excellent results.

Using straight coir, or what we often refer to as pure coir (no additives), will not give you great results without using an organic liquid fertilizer.

We will be testing this soon and will, of course, report the results, whether good, bad, or indifferent.

Thoughts and Recommendations with Coco Coir

We hope that this article answered the question what is coco coir?

We are pretty sure you can know our thoughts on coconut coir. Take a look at our articles on microgreen growing media. 

Coconut coir-based potting mixes perform the best. 

However, using 100% coco coir may not give you the results you want. In our testing, pure coconut coir underperformed against potting mixes that contained peat moss and coconut coir.

Now, we haven't tested watering coconut coir with liquid fertilizer as of yet. But we believe, based on our results with hemp matting and Ocean Solution™, that the coir & Ocean Solution together will grow microgreens very well.

Why We Use Coco Coir

We hope that we answered the question "what is coco coir?"

Coco coir is a renewable product. Even though it has to be transported long distances to use it, it is a better choice than the long-term renewability of peat moss.

The majority of companies that use coconut coir in their potting mixes or buy bricks of coir are, in our option, more socially accountable than other larger corporations. Hopefully, they will make a stand and pressure the manufacturers and growers to be more accountable for the workers' health & safety.

We like that water immediately soaks into coconut coir and isn't hydrophobic like peat moss. 

Coir holds water well but doesn't retain too much, making it an excellent substrate for growing microgreens. 

The wicking ability of coco coir is such that bottom watering is the best way to water microgreens. 

The neutral chemical properties of coconut coir make it easy to include additives into the potting mix that will enhance microgreens' growth. The neutral nature also makes coconut coir an excellent media for hydroponics. 

We Recommend These Coconut Coir Products

The Home Microgreens Potting Mix

This is the potting mix we use to grow all of our microgreens. It is a coconut coir based mix with many natural additives that help grow beautiful microgreens!

home microgreens coco coir potting mix

Visit the Home Microgreens Store for more information on our potting mix.

Author of this Article is Todd

Todd is the founder of Home Microgreens & the Home Microgreens store. He also writes for several other websites, including MakeGardeningEasy.com. Todd worked at a large farm market, garden & nursery center for 20-years. Somehow he snuck off to become a geologist and professor before coming back to his senses to write & lecture about microgreens and gardening. When not at the computer, he can be found in the garden, trout stream, or mountain trail with his new Springer Spaniel Caden.

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  • Very thorough and informative! Thanks!

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