What is coco coir?
Coconut Coir (Coco Coir for short) is a natural fibrous material extracted from the outer layer of ripe coconuts. There are a lot of factors that determine quality when buying coco coir, like whether it has been washed and buffered. Check out our recommendation here for the best coco coir to buy and follow our guide here to get started growing with coco coir.
What is Coco Coir
Coconut Coir (Coco Coir for short) is a natural fibrous material extracted from the outer layer of ripe coconuts. It is sustainably produced, as it’s a waste product from the coconut farming process that otherwise wouldn’t be used. First documented in 11th century AD as being used for creating rope, nowadays it is typically used as a soil-less growing medium for plants, and notably for growing cannabis. Soil-less grow mediums, and coco coir specifically touts many benefits such as faster growth rates, larger plant yields and natural anti-fungal properties over traditional grow mediums like soil and even hydroponics.
A brief introduction to soil-less mediums
Soil-less growing mediums unlike normal soil, do not provide any nutrition to the plant itself. As a result, when growing in soil-less mediums, you have to provide all the nutrition to the plant in the form of liquid nutrients - and as such, soil-less growing mediums are typically seen as similar to hydroponics. With that said there are many benefits to growing in a soil-less medium, most of which are listed below.
Popular soil-less mediums
Popular soil-less mediums include Coconut Coir, Rockwool, and peat moss (Sphagnum moss). Rockwool and Peat Moss both have negative impacts on the environment, and you should avoid use if possible. You can read more about how peat moss negatively affects the environment here and Rockwool here. Coco coir on the other hand is a very sustainable alternative, and it works just as well, if not better than the alternatives. This study compares numerous factors when growing tomatoes using coco coir vs peat moss and Rockwool and found coco coir produce the highest total fruit yield of all three and beat Rockwool in fruit mass too.
Advantages of growing in a soil-less medium
There are many advantages to growing in a soil-less medium over traditional growing mediums, and there are even a lot of benefits over advanced hydroponics methods too.
Faster growth and higher yields
It is known in the growing community that hydroponic-type growing mediums result in faster growth and higher yields. This has been confirmed by my own personal experiences, and also in published scientific articles - there are numerous studies on the topic. For example, this study compares soil and soil-less growing mediums when growing food in limited space environments. It found “The results illustrate that soil-less systems are more productive per square meter, which increases the amount of locally grown, fresh produce available in urban areas.”… than soil systems. This paper discussing the Canadian cannabis growth market confirms that “In Canada, Cannabis is mainly produced soil-lessly in controlled environments…” which include “Rockwool blocks or slabs, in peat moss- or coir-based growing substrates”. In fact, coco coir
Less risk of disease
Another benefit of soil-less mediums is less risk of disease in comparison to hydroponic solutions like deep water culture. Fungus, mold, and algae are less to grow in soil-less mediums like coco coir. Coco coir specifically has natural antifungal, antimicrobial while still providing a healthy environment for good bacteria (we don’t know how this works entirely, research is being done!). This results in protection against bad bacteria like Pithium, while at the same time letting good bacteria like C.Bacillus amyloliquefaciens flourish (like what is in hydroguard).
Little risk for over-watering
Coco coir specifically, has very little to no danger for over-watering. It tends to hold on to the perfect amount of water the plant will need (when matched with an additive to increase soil aeration like organic perlite), and allows excess water to run off. When watering your plant in coco coir, you should shoot for around 10% runoff each day.
Control over nutrient makeup
In soil-less mediums, you are in complete control over how many and which nutrients you are giving your plant. In traditional soil mediums, there is no accurate way to gauge the nutrient levels in the soil and it’s hard to manipulate the level of nutrition in the different stages of plant growth. This will sometimes result in too high levels of nutrition in the seedling stage and too low levels in the flowering stage resulting in slower growth and sub-optimal yields. If you are growing in coco coir, check out our article about the best nutrient formula and schedule for coco coir.
Drawbacks to using a soil-less medium
Soil-less mediums require more maintenance.
- You have to mix your own nutrient solutions according to the stage of growth your cannabis is in.
- Plants growing in soil-less mediums require daily watering with a 10% runoff.
Soil-less mediums typically end up being slightly more expensive than their soil counterparts. This is a result of having to buy the growth medium in addition to nutrients, whereas if you buy good soil you shouldn’t require additional nutrients (but you will have slower growth).
Getting started with coco coir
How is coco coir made?
- Harvested coconuts are first soaked in water to allow them to begin to break down, a process called retting. This process makes it easier to remove the outside layer of the coconut husks, which is eventually used for the coir.
- After the coconuts have been properly retted, the coarse fiber and coir dust are removed from the outside layer of the coconut husks. At this point, the fibers and pith are decomposed more.
- The coir is then washed to remove excess salt accumulated in the process of retting (if it was retted in saltwater).
- The last important step is the buffering of the coir.
After the coconuts have gone through the retting process, the coco pith is extracted from the coconut and is allowed more time for decomposition. At this point, the product extracted is a mixture of short fibers and corklike particles that range in size, including a dust-like substance. Many coco coir companies ret their coco coir in saltwater. This is okay if the coir is washed before selling to the customer but some companies don’t do that. If it is not washed, it could be highly salty and kill your plants! Cheap coco coir companies do not spend enough time in the retting/decomposition stage. As a result, their coir is not optimally broken down and can result in a high nitrogen draw down index, likely resulting in nitrogen deficiencies even though you may be feeding your plant the correct amount of nutrients!
Because coco coir is a byproduct of processing coconuts, there is a wide variety of qualities when it comes to purchasing. Coconuts are typically grown and processed in salty environments and as a result, many of the coconut coir products on the market contain high levels of these salts. Additionally, many coco coir brands ret their coconuts in saltwater. For obvious reasons, high levels of salts in your growing medium for cannabis or any plant will cause a myriad of serious issues, likely resulting in either a dead plant or severe nutrient imbalances. To avoid this, you need to purchase coco coir that has been adequately washed to remove these excess salts or choose a brand that rets their coco coir in freshwater.
Coco coir naturally has a high cation exchange capacity and retains calcium, phosphorus, and iron. This results in retaining excess nutrients within the medium for a while until the medium becomes “saturated” in which it doesnt hold on to additional nutrients. To solve this problem (and avoid getting nutrient deficiencies while the medium is new) you can follow a guide on how to buffer to coir yourself, or you can buy pre buffered coco coir. Buffering the coco coir saturates the medium with nutrients so you wont run into deficiencies while the coco coir is new, even though you are using the correct nutrient levels.
What coco coir is best?
We recommend the brand “Canna” as they do a very good job at cleaning their coco coir, and they treat their product with calcium and magnesium.
How grow marijuana in coco coir
Follow our guide for growing marijuana in coco coir here, which includes suggestions on products used for growing, and the optimal nutrient schedule for growing weed in coco.
Q: Is Coco Coir better than soil?
A: If your goal is to produce the largest yields as fast as possible and don’t mind the slight additional work and costs involved, yes coco coir is better than soil. If watering your plant daily, and mixing nutrients sounds like too much work, you are likely better off using plain soil.
Q: Is Coco Coir good for plants?
A: Yes if you provide the correct levels of nutrition, water often enough, and choose high-quality coco coir, that has been washed and buffered.
Q: What are the best nutrients for Coco?
A: There are many formulas for growing plants using coco coir, primarily because most hydroponic formulas can be used with slight modifications. With that said, the Ironhead method is the best nutrition schedule we’ve found for growing marijuana in coco coir. Check out our guide for growing marijuana in coconut coir using the Ironhead formula.
Q: Can you use Advanced Nutrients in coco?
A: TODO, but our recommendation is using the Ironhead method for fastest growth and largest yields. Check out our guide for growing marijuana in coconut coir using the Ironhead formula.
Q: Does Home Depot sell coco coir?
A: Yes home depot does sell coco coir, but they don’t always have the highest quality brands. Remember, you need to find a brand that washes and buffers their coco coir. For that, we recommend the Canna brand, where you can order on Amazon here. Remember, dehydrated bricks of coco coir tend to be of lower quality, so be sure to scrutinize the packaging and company before purchasing (Canna is a rare exception to this rule).