(Photo by: 
Hey there Cannabis Community! Today I would like to talk about Coconut Coir or Coco Coir for short. For those of you that know and have experience with this medium- please chime in! For those of you who have not heard of this or would like to give it a go- read on! Many growers are used to growing Cannabis via bagged soil usually found in hardware stores, and other growers a bit more versed in hydroponics are used to growing in the many techniques of hydro, but what about the middle ground that utilizes both soil and hydro principals? Coco Coir is exactly that: the middle ground called Soilless that has the benefits of both soil and hydro. This article is not meant to say that it is better then either, but rather it is here for information and to raise awareness to just another technique in the space of Cannabis culture.
What Is Coco Coir?
It is exactly what it sounds like: it is the fibers found inside of a coconut! Millions of husks produced in coconut regions (Southeast Asia, Mexico, India, Sri Lanka) are scooped out and rinsed to then be bagged. Some of you who may be Agriculture majors may ask, "but aren't coconuts grown in tropical areas near the ocean.... which means salt accumulation?" The answer to that is absolutely, and for that reason coco coir is rinsed and buffered until it reaches a reasonable EC (electrical conductivity, more on this a bit later) to then be shipped off. It usually comes in various forms: finely graded like soil particles, roughly chopped like thick pieces of hair, and somewhere in the middle that has both. It generally comes dehydrated in the form of a brick or sometimes in the more expensive products it comes semi-hydrated in a bag. That is one of the major benefits that I have come across with using this medium- the fact that you can transport large amounts of it with very little space and not having to worry about breaking your back carrying it all. The bricks that I am accustomed to getting usually were 15 Liters and once fully hydrated turned into 30 Liters. Once again, it is an alternative to soil and hydro growing but does have the benefits of both, as well as negative issues (as does everything).
(Photo courtesy of TheWormFarm.net. The difference of a brick of coco and hydrated coco)
The Technical Side of Growing in Coco Coir
The technical aspect can get most of us confused especially if you did not do well in your chemistry course. As we already know, coco coir is from coconuts which retains a large amount of salt. Luckily, most producers rinse this away and re-buffer the medium. Sadly, it does not end there because of the CEC (cation exchange capacity) of the medium. Coco is able to hold large amounts of Potassium, Magnesium and Calcium. Most of us would think that is a good thing, right? In this case it isn't because the CEC can also lock-out K, Mg, Ca and other vital nutrients to cause nutrient deficiencies if not kept in check. This is why producers generally buffer coco coir before it is packaged: to fill the CEC with the correct ratios usually with Mg and Ca. The CEC is like a bank, it enjoys having its spots filled with the correct amount; but it does not react well when it is over-drawn or empty. This issue with coco may seem daunting at first, but as with anything you will need to see how it works in your environment and you may find that this medium is very approachable.
The Benefits of Growing in Coco Coir
In regards to growing Cannabis, most of us would like to grow in something that is fairly simple to use, keeps our plants happy and is sustainable. I feel that coco does hit all three of these mark.
Sustainability: Firstly, coco is organic and re-usable. All that needs to be done is for it to be rinsed and re-buffered and then it can be re-used. It does not break down quickly and can handle many subsequent crops. If you aren't confining your plants to pots then you can add coco directly to your soil mix. It retains a large amount of water, meaning you do not have to irrigate often which then saves water (especially if you are in a drought zone). It's from coconuts so it does eventually bio-degrade unlike other materials that are from natural materials but will never break down (Rockwool). Of course the negative implication can be that it lends a hand to coco production and land clearing for more coconut tree farms. This is very much so a fact but to which extent is debatable; considering most claim that since coco coir is a by-product of coconuts that already are harvested for their juice. You do not need to use inorganic nutrients with coco! This being one of my favorite parts of growing with coco is that you do not need to use fully synthetic fertilizers.
Usability: As already stated, there is definitely a learning curve with coco. You should really do research on the chemistry behind coco coir as it will save you a few headaches in the future. It's extremely easy to carry (when dry and bagged), it does not take up much space (when dry and bagged), does not have a strong smell, and cleans up very easily. You will need a pH meter or EC meter to every once in a while check your runoff to see what range you are in. Checking your EC will let you know what is going on below the surface and give you invaluable information if growing in pots.
Plant Health: Once you get your stride with growing in coco you will absolutely see the major benefits. Rapid growth as seen with traditional hydroponics and a lushness that seems the remind me of growing in organic soil. Because of the structure of coir the root system will thank you for the added aeration and the remarkable water retention. It does great for insulation which will benefit your plants root system in hot or cold weather. Another major bonus is that it is not prone to rot. Roots tend to spread quick within the medium and it is normal to grow very large plants in small containers. It is very easy to flush coco plants, so if you do notice too high PPM/EC, then it is not that difficult or messy to do!
Tips
My ultimate rule for when growing in coco coir is never let the soil dry out! This is a major situation with coco that has created a headache or two for me in the past, but letting your medium completely dry out will lead to nutrient lock-out due to salt accumulation. Nutrient lock-out and high levels of salt are definitely the opposite of what you're looking for. My rule of thumb has always been to lift the pots, and once it felt like they were 1/4 full of water it was time to water again. Everyone has their own methods that they make over time and especially in their given circumstances... so soon you too will figure this out!
This is mainly a situation of growing in pots with 100% coco, but it would not be an issue if mixed with soil and outside.
If growing in pots- always add Dolomite Lime that is finely grounded. Dolomite Lime is an organic source of Ca and Mg, two major nutrients that need to be kept in check when it comes to growing with coco. There are other options such as CalMag but if you'd like to go for the organic route then look no further then Dolomite Lime.
You can always mix other mediums into coco to further customize it to your style. Think of worm castings, perlite, compost, or anything else that comes to mind!
That's it for today on growing with coco! I hope everyone's garden is on its way to a healthy harvest!