There are many different types of coco products on the market. The husk of coconuts yields not only very coarse long fibres which are used to make a wide range of products such as rope, carpets, mats, brushes, basket liners and others, but between these coarse fibres is a corky substance called coir pith, coir dust, coco peat or coir peat. Many grades of horticultural coco exist and some have been specifically designed for different plants and systems. The very fine particle size of coir dust retains a high level of moisture and this is suited to seed raising and for smaller seedlings and plants. While a high moisture holding content in fine coco dust is an advantage in some situations, it can create problems with over saturation of the root zone. Grades of coco often used in slabs may consist of larger particles or `flakes’ of coco which allow a good degree of drainage and resist packing down over time as commonly occurs on substrates such as peat.
For an extraction test, a small sample of coco is taken from the growing media, (several samples should be taken and combined to give a representative sample). Then 100ml of these combined samples is measured out (coco should be damp but not overly saturated). The 100ml sample of coco is placed in a jar and 150ml of deionised (or RO) water is added and the mixture shaken 50 times. This is allowed to sit overnight to allow extraction of nutrient ions in to the water. The resulting mix is then re shaken and filtered to remove particles and the pH and EC can be measured.
Coco fibre is also the term often used to refer to the general purpose grade of coco which is ideal for growing longer term crops under soilless cultivation. Worldwide coco is used for soilless crops such as tomatoes, peppers, cucumber, melons, aubergines, ornamentals, cut flowers and many others because the structure of the coco does not break down over the time frame these longer term crops are grown for. Thus high rates of root zone aeration and moisture retention are typical in both short and long term soilless crops and this results in high yields and good root health.
Different types of coco products – uses, pros and cons
Coco also comes in a range of different products – from small to large compressed `bricks’ to `grow slabs’ to pre expanded ready to use, bagged product. Compressed bricks of coco fibre mean the cost of shipment can be kept to a minimum, a typical 5Kg block of compressed coco can be expanded in water to over 65 litres of ready to use growing substrate. Pre wrapped slabs of compressed coco can be less than one inch thick but when expanded with water within their plastic sleeve give a full sized growing slab comparable in volume to rockwool. The advantage of coco bricks is that once expanded the media can be used to fill any size or shape of growing bed, pot or bag, the disadvantage is that a time is required for the media to fully expand and some labour is needed to fill the growing plots.
- Always invest in a good quality, well known brand of coco designed for soilless growing and don’t be fooled by the many inferior quality products on the market. While coco from different sources may look similar, there can be large differences in the quality and this can have a negative impact on plant growth. Coco products sold in garden stores and hardware outlets often as inexpensive compressed bricks of `garden mulch’ are not usually suitable for soilless growers – these types of coco are typically high in sodium (an unwanted element), high in total salt content, often have not been fully decomposed, and hence have a high nitrogen draw down which can result in nitrogen deficiency even when the full strength nutrient solution is applied. Inferior coco products are also not `buffered’, `conditioned’ or `pre-treated’ to stabilise the potassium levels and boost calcium which is required to offset the tendency of coco to retain calcium. They may also contain weed seeds and pathogens. Buying a reputable brand of coco for soilless growing is an important investment in the nutrition and health of the plants and also simplifies the process of growing a great crop.
- Select the right nutrient product (i.e a specific coco nutrient product) to use on coco substrates. Coco growing media is not like many other soilless substrates such as rockwool which arrive pre sterilised, chemically inert with a low CEC and with a very minimal effect on the composition of the nutrient. Coco contains naturally occurring potassium which since potassium is a major plant nutrient, is considered a bonus; however this needs to be allowed for in the nutritional program of the plants. Coco also has other effects on the composition of the nutrient solution applied and levels of nitrate, phosphate, calcium, magnesium and iron may need to be adjusted to allow for these properties. There are commercial brands of specific `coco nutrient’ formulation products on the market, however it is always a good idea to select both the coco substrate and the coco nutrient of the same brand as it is likely they have been developed to work together and will give the best results. High quality coco products are likely to have been pre-treated and the accompanying coco nutrient will take this into account so that the ratio of elements in the root zone stays as optimal as possible.
- Select the right type of coco product for the plants being grown. There are a large range of coco products on the market and many different grades with various horticultural uses. While orchids prefer a very coarse coco `chip’, using coco for propagation and germination of small seeds requires a much finer grade which will hold sufficient moisture as well as oxygen. General purpose coco which consists of a range of particle sizes is considered ideal for many plants and is the most widely used grade for soilless production. The coarser particles help the coco substrate remain more `open’ to aeration while the finer particles hold moisture between irrigations and the combination of both these, is what gives coco close to optimum physical structure for plant growth.
- Remember that coco is a `living substrate’ and it should be treated as an entire eco-system which consists of beneficial microbes who make their home in the coco particles. This beneficial microbial life plays an important role in soilless systems as many fungi have a protectant effect on the plant’s root system and have been proven to suppress plant pathogens as well as other possible benefits with nutrient uptake and plant growth. While other growing substrates start out as sterile, coco is best left in its original state or even inoculated with populations of beneficial microbes such as Trichoderma. These populations of beneficial microbes in coco are to be encouraged and for that reason harsh sterilising chemicals such as chlorine bleach, hydrogen peroxide and even boiling water should not be used on coco substrates at any stage.
- Coco usually maintains pH within an optimal range; however EC can build over time and should be checked from time to time, particularly under warm growing conditions where the plant may have been taking up a lot of water from the substrate, allowing the concentration of nutrients to climb. Because of the nature of coco growing media the EC around the plant’s roots may be different to that in the leachate or the solution draining from the growing slabs, pots or bags. A quick and simple `extraction sample EC test’ can be carried out on coco media to determine the actual EC around the root zone.
Tips and tricks when using coco
Loose coco placed into growing pots or containers can be easily inspected for moisture level by checking the appearance of the top of the substrate or by feeling the moisture level of the coco just below the surface, this is more difficult in wrapped coco grow slabs. The coco slab only needs to be placed in position, slits cut in the plastic sleeve and water poured in – the coco expands and can be planted out with no further effort. The disadvantage of slabs is that they need a very level surface to sit on so that drainage is even and they don’t provide the depth of growing substrate that a planter bag or pot can for larger plants.
Often, piles of coir dust were not left to decompose sufficiently and the resulting coco had a high nitrogen draw down index, this meant that under soilless cultivation, even with well balanced nutrients, nitrogen deficiencies in the early stages of growth were common.
Any quality cannabis nutrients made for hydroponics will work well for growing in coco coir as long as you also use a Cal-Mag supplement.
However, this tutorial focuses on coco growing that doesn’t involve any soil or non-inert ingredients, in order to achieve the fastest growth. You’ll learn how to grow with a coco/perlite mix and provide nutrients in the water. This root environment creates thriving cannabis plants.
You don’t need any other nutrients to grow marijuana; the Flora trio + Cal-Mag will give your cannabis plants what they need to flourish through the vegetative and flowering stages.
Step-by-Step Grow Cannabis Coco Coir Tutorial
Note: “Coir” is officially pronounced “coy-er” but I’ve noticed most cannabis growers say “kwar” (rhymes with “car”).
Here are some additional nutrient suggestions for growing in coco coir:
If you followed the above tutorial to make your own coco mix, you’ll have about 10 gallons of potting mix. This can be used to fill 2 x 5 gallon pots, 3 x 3 gallon pots, or 5 x 2-gallon containers.
Now you fill the rest of your fabric containers and possibly solo cups for seedlings.
Professional cannabis cultivators all agree that drainage and aeration are key to a successful crop. Many achieve this by using coco coir as their growing medium. Coco coir, if you’re not familiar, is produced from the humble coconut, specifically the fibrous material found between the husk and the coconut itself. This material holds water well but also allows for good drainage. (I know it’s hard to wrap your brain around being both water-holding and water-draining at the same time, but let’s chalk it up to science.) Well-draining growing media allows for good air flow, which is good for root growth. And a good, healthy root system is the secret to a great crop of pretty much anything, including cannabis.
We at Organic Mechanics think our Cocodelphia coco coir product is one of the best on the market. Why? For one thing, we buy our coir from just one farm in India, so our variability in quality is essentially non-existent. That farm washes the coir several times and relies on the monsoons of Southeast Asia to accomplish this. Once we have received the coir, it’s washed again as we rehydrate the air-dried, compressed coir blocks. Essentially, Cocodelphia is triple washed.
What Is Coco Coir?
If you’re just beginning to grow cannabis legally, you’ll want to grow it correctly. While we won’t get into the day-to-day details of cannabis production here, we will explain how to get your cannabis crop off to the best start possible. It all starts with your growing media (and we know growing media). Specifically, one growing media of choice for many growers is coco coir.
The Science of Coir
I mentioned “science” above, and it turns out “science” is a key aspect of why coco coir is an ideal medium for growing cannabis as well as other crops. Some of the properties of coir that allow crops to thrive when grown in it include: