In the search for a peat moss alternative, coir, also called coco coir, is the one that is most often discussed. Coir is made from the outer husk of coconuts and is a waste product from the coconut industry. Environmentalists are quick to point out that “since it is a waste product, its use is more environmentally friendly than using peat moss.” How can such common-sense logic be wrong?
What is Coco Coir?
A coconut consists of two main parts: the inner coconut kernel, which we eat, and the outer husk. The outer husk consists of fibers and corky material found between the fibers. The fibers are extracted and used for many applications, including floor mats, doormats, brushes and mattresses. The remaining dust and short fibers are known as coir pith.
In horticulture, the term coir is used interchangeably with the term coir pith and is sometimes called coir peat, coir dust, coir meal or coco peat. The material is brown, sawdust-like and looks similar to dry peat moss. Most of the coir used in horticulture comes from larger coconut fiber processing mills located in Sri Lanka and India.
In some cases, the husk is simply broken into chunks without removing the fiber and sold as potting media for plants like orchids. The exceptional water-holding capacity and airiness of the material make it a perfect medium for such plants.
Choir has many of the same properties as peat moss, including the ability to hold a lot of water. It is sold dry, but after soaking in water, it expands 3-4 times in size as it soaks up all the water. Coir tends to have high levels of potassium and low levels of calcium (ref 4). It is not a perfect substitute for peat moss, but for this post, let’s assume it is good enough to be used as an alternative potting medium.
The key question then becomes, is coir more sustainable than peat moss? If it is, we should certainly consider switching to it. If not, we might as well stick with peat moss.
What is Sustainability?
There is so much talk these days about products being green, eco-friendly, or environmentally friendly, but what do these terms really mean? I’ll bet most people can’t explain what they mean except in very vague terms, such as “it is a product that is better for the environment” or “it is sustainable” – another term that gets thrown around and is rarely understood by the general public, including me. I had to look up the definition. You probably have a sense of their meaning, but can you define them?
Wikipedia defines environmentally friendly as having “minimal, or no harm on ecosystems or the environment.” By that definition, there is not much we humans do or use that would qualify. Neither coir nor peat moss meets this standard. However, in our quest to harm the environment less, we can use this definition to compare two options to see which does less harm to the environment.
Sustainability is “the study of how natural systems function, remain diverse and produce everything they need for the ecology to remain in balance” (ref 2). It measures how much damage something does to the environment and society – note the word society – it is not just about the environment.
Our Perception is Easily Confused
Humans are not good at using logic to compare two options for eco-friendliness, and peat moss is a good example.
Coir is a waste product, so immediately, people assume that using it has very little environmental impact. When I asked people about the environmental impact of shipping the product halfway around the world, they dismissed this issue and focused solely on the fact that it was a waste product. It is a myth to think that using of a waste product is automatically eco-friendly.
Newspapers and environmental sites flash pictures of the raped peat bogs in Canada as evidence against peat moss. These are strong images and people respond deeply to them. Add to that the fact that many people know that our wetlands are in danger. Without any real facts, people quickly conclude that this is a catastrophe and that any other option must be a better option.
If we really want to make a difference to the environment, we have to start asking for real data. We can’t rely on common sense and gut feelings.
Is Coco Choir Sustainable?
A recent study (ref 1) looked at this question in great detail. They tried to quantify parameters for many aspects, including:
- Key materials in the supply chain
- Economy
- Biodiversity
- Water, air, and soil pollution
- Water consumption
- Energy consumption
- Culture and working conditions
It would be nice if such studies resulted in a sustainability number that could then be compared to the sustainability number of other options, but it doesn’t work that way. Instead, the study highlights areas of concern, what they call hotspots. The following are some hotspots for the coir manufacturing process (full details can be found in ref 1).
Processing Coir Pith
Creating coir pith requires more than just physically separating the fiber. Once the coir is freed from the fiber, it goes through a maturation process to stabilize the product, and this can take up to 6 months. During this process, salt, tannins, and phenolic compounds are removed. It is buffered, washed, and calcium nitrate is added to displace sodium and balance the pH.
This process requires input chemicals, and it produces waste products.
Water Consumption
Processing coir requires a significant amount of water, and in some areas like India, water is already in short supply. It takes 300 to 600 liters of water to wash one cubic meter of coir pith (80-160 gallons per 1.3 cubic yards). The result is polluted water that impacts the environment.
Comments such as “the horticultural use of coir helps solve a waste disposal problem” do not hold water.
Worker Health
The whole process is very dusty and creates an unhealthy environment. Workers in coir pith factories often work six-day workweeks with multiple shifts. We don’t normally think of this as a factor in sustainability, but it is.
A study on this concluded that “coir work induced nasobronchial allergy and pulmonary function abnormalities” (ref 5). In North America and Europe, it would be illegal to work under such conditions.
Nutrient Depletion
As coconuts grow, they remove nutrients from the soil. If the resulting coir is now shipped overseas, it can’t be used as a local organic source to replenish the missing nutrients. The result is that more fertilizer needs to be brought into the plantations to grow coconuts, which has an additional environmental impact.
Small coconut farmers are not sending their coir for processing and instead use it as a fertilizer source. But this will change as the demand for coir increases.
Coconut plants are renewable – new trees bear fruit in 6-10 years. But the soil being used for growing them is not renewable if the majority of the organic matter is shipped overseas.
Conclusion: Coco Coir is Not Sustainable
Many websites claim that coir is sustainable since it is a waste product. Packages of coir even have the word on their label, telling customers they are eco-friendly. It is simply not true.
Coir requires significant processing that uses input resources and produces waste products. It also poses health risks. Perhaps the most significant long-term problem is the depletion of soil nutrients.
Admittedly, there are degrees of sustainability, but I think it is a stretch to call coir sustainable or environmentally friendly.
Coir vs Peat
Use of either coir or peat has an impact on the environment, so which one is worse?
There is not a lot of good data on this yet, but I did find one study that looked at this problem. A study by Quantis looked at the environmental impact of various soil-less mixes to try to determine which had the least impact (ref 6).
The study looked at the complete life cycle of the material: production, delivery, processing, distribution, use, and end of life. It considers impacts on climate change, resources, human health, and ecosystem quality. It concluded that “it is not possible to identify any among the growing media as the least or the most impacting across all the indicators” (ref 6).
Peat moss affects climate change and resources the most. The impacts of peat include transportation, land use change, CO2 production, and aquatic eutrophication (loss of bogs).
Coir affects human health and ecosystem quality more than peat. The impacts of coir are due to transportation, electricity consumption, use of calcium nitrate for buffering, land occupation, and production of particulate matter.
Is Coir a Good Alternative to Peat?
From my previous posts, Peat and Peat Moss The True Story and Peat and peat Moss Alternatives, it is clear that the use of peat in horticulture does not have a significant impact on the loss of peatlands. Year over year, the amount of global peat is increasing faster than it is being used. Some 86% of global peatlands are untouched by humans – there is no environmental catastrophe.
If society wants to reduce peat use, their efforts need to be focused on agriculture and forestry, not horticulture, which uses less than 1% of the yearly peat harvest.
However, it does make sense to reduce the use of peat as a soil conditioner. There are better options that have less environmental impact. Finding an alternative to peat moss for the cultivation of plants in pots will have little environmental impact.
Coir may be a suitable alternative to peat for pot culture, but it also has environmental issues. Based on current data, it is not more environmentally friendly than peat. The environmental cry to replace peat with coir is unfounded. This is especially true for societies that live close to peat sources, where transportation of peat can be kept to a minimum.
References:
- Coir: A Sustainability Assessment; https://randd.defra.gov.uk/ProjectDetails?ProjectId=18114
- What is Sustainability; https://www.environmentalscience.org/sustainability
- Spotlight on Coir Pith; http://www.ethicalconsumer.org/ethicalreports/gardening/coirpith.aspx
- A Comparison of Coconut Coir and Sphagnum Peat; http://cpl.usu.edu/files/publications/factsheet/pub__9468201.pdf
- Abnormalities Among Coir Workers of Alappuzha; https://japi.org/r2a4c4b4/serum-ige-level-among-coir-workers-with-asthma-a-hospital-based-descriptive-study-from-alappuzha-kerala
- Life Cycle Assessment of Horticultural Media; https://erden-substrate.info/wp-content/uploads/2023/02/comparative-life-cycle-assessment-of-horticultural-growing-media-based-on-peat-and-other-growing-media-constituents.pdf
- Photo source; Richard Allaway
Love the way you challenge conventional ideas – thought provoking and seems based on facts and science rather than emotional responses or vogue thinking. A distinct absence of pyramids and crystals that lends credibility to your briefings. Thank you.
I just returned from the Mother Earth Fair in Portland and someone was selling stone pyramids – I thought that was debunked 30 years ago.
Regarding the stone pyramids in Portland, I just have to say, it’s Portland Oregon, I live less than an hour south an EVEN I think people in Portland are weird. There are many people there who reject anything scientific that doesn’t mesh with their beliefs and say studies that debunk them are conspiracy. Not all Portlanders are that weird, but it’s more common there (and in Eugene) than in most of the rest of the state. If you have ever seen the TV show Portlandia, then know that, while it is sometimes rediculous, you can find people true to it in Portland.
Thanks. A good read. Most issues involving environmental impact are more complicated then they first seem
Environmentally coir is an almost unmitigated disaster and as a compost ingredient is next to useless – in my opinion!
🙂
I appreciate your research and logic here. I live in Thailand, where I suppose this is indeed a sustainable resource. I had no idea of the processing the stuff goes through. I wonder if the stuff produced in Thailand does go through this process at industrial scales. I suppose though that small processors just chop the husks either by hand or machine, stuff the chunks into sacks, and sell them 😉 Aside from chunks, yes, fiber strands are available, and I suppose I’ve seen the sawdust-like stuff.
Only part of your article that I’d like to discuss regards nutrient depletion part. C’mon … is there any substantial loss of nutrient to the soil by sending the husks off the land? It seems to me I’ve read of research (haven’t seen an actual paper) that says that the loss of soil nutrients due to harvesting plants is infinitesimally small. In addition … if Elaine Ingham is correct in saying that (the great majority of) all soils on earth have way way more soil nutrients than necessary for plant growth, then the issue of Nutrient Depletion is moot. If I remember correctly, you’ve taken issue with Elaine in the past, so I wonder what you have to say about her claim on this. Maybe you’ll stand by this claim of nutrient depletion.
🙂
Re: “if Elaine Ingham is correct in saying that (the great majority of) all soils on earth have way way more soil nutrients than necessary for plant growth”. I have not researched this claim. Consider this, we know for sure that adding extra fertilizer to farms makes for larger harvests. Given that, how can we conclude that the farms have more nutrients than the plants need? It depends on how you define “plant growth”. Sure the farm soil has enough nutrients to grow some kind of plant – weeds will do just fine. If plant growth is defined as producing suitable yields of specific crops, then I think it is clear that her statement is wrong in reference to farming.
However, in home gardens, especially landscape gardens, the statement might be true.
Is the removal of husk important for local soil? Lets ask a different question, do coconut farmers add fertilizer to their fields? If they do, then yes the removal of husk makes the situation worse. If they don’t, and nutrients levels remain the same over long periods of time, then the removal is insignificant. I am fairly sure they fertilize.
I am somewhat familiar with Elaine Ingham work. Her statement regarding nearly every soil containing more than enough mineral nutrients for plant growth is specifically made with regard to farmers. Her point is that traditional farmer methods destroy the soil components that are needed for making those mineral nutrients available to the plants. The necessary components are bacteria, protozoa, fungi, nematodes, microarthropods, earthworms, etc. See, for example, https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053865
I am aware of her belief that synthetic fertilizer kills soil microbes, but that is not supported by science. Her ideas of the right ratio of bacteria to fungi is also not supported by science. I have discussed some of this in my review of Teaming With Microbes.
I don’t think I was terribly clear in my previous post. I guess what I’m saying is that, given how peat and coir are used—especially as a general soil amendment—wouldn’t any fibrous plant waste do the same job?
For soil amendment – yes. That agrees with what I said.
Maybe this is stating the obvious, but why not use whatever organic waste is available locally instead of using something that must be shipped thousands of miles? By local, I don’t necessarily mean just down the road, but say, within a few hundred miles.
Even the residential neighborhood in which I live seems to produce a lot of bio-waste as people go about their garden, tree, and lawn tending activities. We put it in dedicated bins for pickup by the recycling company, who in turn sells it to a composting company. Where it goes from there, I don’t know, but I certainly don’t see bags of amendment and mulch labelled “Sourced from North Central California” sold in the garden stores here.
And wouldn’t it help if more people kept and composted their own gardening waste? I keep as much of mine as I can. If I had a small wood chipper, I would be able to keep even more. I don’t generate a lot of coarse woody waste, but I do end up having to send rose and shrub prunings off to wherever it goes on pick up day. It almost kills me to see all those nutrients and potential mulch leave my yard! Worse is that, when I need such waste, I have to buy it, and who knows how far the stuff had to travel or under conditions it was produced. But, people around here don’t seem to retain their yard waste for their own use, and that’s a shame. I almost want to cry when I see great piles of wonderful autumn leaves swept off into the street for disposal by the city. I don’t have any trees, so I would kill to have such leaves!
So, wouldn’t retaining and processing our own yard waste be, in the long term, more generally eco-friendly and sustainable? I know—that would probably be asking too much of the casual gardener who just wants a nice looking front yard.
In the previous two posts I make the point that the use made of the material is important. For amending soil, almost any local organic matter should be used. When talking about container grown plants, consistency of material becomes important and most local organic material does not provide either the consistency or the specific features required.
Cynthia, I am SO with you and your ideas of use and waste. Here in central CT, I compost all vegetable and fruit scraps, garden waste, except, like your rose trimming situation, I usually discard tomato stalks because of the possibility of transmitting disease to the next year’s plants. I too wish for a small wood chipper to grind up and re-use tree trimmings. I usually even collect with my car trailer bags of leaves neighbors put out for municipal pickup. Such a waste of a valuable resource.
I had a small wood chipper. Found it takes too long to chip anything and it uses a lot of gas. Now I just pile up the sticks and let them decompose – granted I have room to do that.
Nice article. Again you take a poke at “transportation” issue. I don’t think most gardeners consider this in purchases of conditioners, compost, fertilizers, even soil.
I don’t think they consider in any of their purchases.
“If society wants to reduce peat use, their efforts need to be focused on agriculture and forestry, not horticulture which uses less than 1% of the yearly peat harvest.”
On the face of it, that statement (unlike peat) doesn’t hold much water. So what is the remaining 99% of the peat harvest used for? Agriculture and forestry? Surely not!
How, by what means and for what purpose is peat ‘harvested’ for agricultural and forestry purposes? If you are referring to land reclamation for agricultural and forestry purposes, then one might suggest that you have misconstrued something. Land reclamation for these purposes generally takes place on cutaway or cutover peatlands – i.e. peatlands where the peat has already been removed: harvested, most likely, for other purposes, such as horticulture or as fuel for heating, electricity generation but not, in the first instance, for purposes such as agriculture/forestry/etc. These kind of activities only come into play after the harvest.
It hardly needs pointing out that horticulture is a branch of agriculture. However, the author seems to exclude it from his ‘finding’ that agriculture, together with forestry, accounts for the greater part of the ‘yearly peat harvest’. But if this harvest is not being used for horticultural purposes, then what? It’s not being fed to livestock or used in tillage. So what other branches of agriculture could account for the use of peat, far in excess of that consumed for horticultural purposes?
For the most part peat lands are used for forestry, and yes peat is harvested to modify agricultural soil. Have a look at the references I provided – I did not make up these numbers.
Great post, Robert. This is very good to know — thank you!
Every product imported from a distance should be tagged with the carbon footprint of transporting it from its source.