autoflower coco coir

Growing Cannabis In Coco Coir Or Peat Moss

Growing cannabis in soil alone offers good results, but soil amendments such as peat moss and coco coir can make good results great. They add structure, hold water, improve acidity, and boost microbial life.

Growing marijuana in coco coir is a fantastic alternative cultivation style. For beginner growers and those more practised in typical hydroponics or soil substrates alike, coco coir cultivation is easy to learn. By the end of this blog, you will be fully prepped for a coco coir cannabis cultivation experiment.


Coco coir is the recycled and processed natural fibre from the husk of coconuts, grown mostly in India and Sri Lanka. What was once regarded as waste material, in contrast today constitutes a magnificent growing medium for cannabis plants both indoors and outdoors. With a pH of typically between 6.5-7.0, coco coir is comparable to unfertilised soil. Coco coir is available from most grow shops in 50l sacks. It’s sold just like soil. But usually more readily available in tightly compressed coco bricks.


In the last few years, most soil growers have begun blending coco coir into their own homemade super soils. Even the manufacturers of most common grow shop soils recommend buffering the substrate with coco coir these days. Coco coir drains better and keeps the roots oxygenated more than standard peat-based mediums. So you already have experience cropping in soil. Why not dabble with a soil and coco coir mix before making the switch?

Most coco coir growers like to add approximately 30% perlite to the mix for best results. Although a lot of growers are also mixing clay pebbles in at a similar ratio. With equally great results. So much so, that premixed blends of coco coir and clay pebbles can be found in some online grow stores.

If you have coco coir in brick form, make sure to purchase a high-quality brand. Every brick will be relatively uniform. When you add 4-5l of water and leave it to soak for about 30 minutes, a consistent 9-10l of medium will be produced from each brick. Simply add perlite and mix by hand in a good-sized bucket.

Low-grade coco coir bricks can sometimes be overdried. Occassionaly they can have odd sizes. Worse, some can be really tough to break down into usable growing medium. No matter how much water you add, bunk bricks won’t crumble easily.

Jiffy pellets are made from coco coir. Jiffys have been popular rooting mediums with growers for decades. Cuttings and seedlings once rooted can be transplanted into virtually any other substrate. Alternatively, you can use 1l starter pots filled with coco coir mixed with 30-50% perlite and transplant to larger containers of your preferred substrate later.


Watering and feeding cannabis plants cultivated in coco coir is a relatively simple transition for hydroponics growers and organic growers. Generally, hydroponic fertilisers perform better than most brands’ organic soil nutrients in coco coir. Specifically, coco specific nutrient ranges are worthy of consideration.

Coco coir is more forgiving than most hydroponic mediums, but not quite as an effective buffer as soil. That being said, you absolutely can hand-water cannabis plants in coco coir as one would soil cultivated marijuana. Moreover, the grower can assess when to water by picking the pots up. Light and dry just as is the case with soil. That’s your cue to water.

Coco coir unlike most soils for cannabis cultivation is unfertilsed. This is where hydro growers get to transfer their skill set. A light nutrient solution must be applied just like in a hydro crop from the beginning. The pH of your water will have to be adjusted to ensure you stay at the sweet spot for coco coir, namely a pH value of 6.0. In order to accurately keep the pH and nutrient solution dialled in, you have two options.

The simple option is to purchase high quality nutrients with pH perfect blends. Alternatively you can use standard hydro equipment. A pH meter and bottles of pH-Up and pH-Down will do the job. So you can either let the wonder nutrients work their magic or dial in the old fashioned way.

Without coco specific nutrients you will pretty soon discover, that coco coir doesn’t retain calcium very readily. Dialling in the nutrient solution can be tricky for beginners. More so with a mix and match of hydro nutrients and supplements. Iron is another missing micronutrient in coco coir that growers experience deficiencies with and often never resolve, thus reducing the final harvest. Start with the coco specific nutrients and you won’t have to troubleshoot later. Especially if you are a first-time grower.


Peat moss also makes a useful soil amendment. Also known as Sphagnum, peat moss is a genus of around 380 separate species of mosses. Peat moss works to acidify its environment by uptaking cations like magnesium and calcium, and in turn releasing hydrogen ions. By outputting hydrogen, peat moss slowly builds bog-like conditions that can reach deep into the ground. In nature, the mosses eventually form a peat bog.

Growers need to properly prepare peat moss before adding it to a soil mix. The moss is known to be particularly resistant to absorbing water at first, and therefore needs to be well-moistened. To do so, place the desired amount into a deep tray. Spread the peat moss out across the tray and leave it exposed outdoors for several weeks. Allow dew and rainwater to soak the moss, but drain the tray as soon as the water begins to collect. If you live in a dry region, manually soak the moss before it dries out.

After several weeks have passed, add the peat moss to equal parts organic potting soil and perlite. Thoroughly mix them in a large bucket. The perlite will help to aerate the mix and keep oxygen flowing through the soil.

Peat moss will add beneficial microorganisms to the soil. Before planting, add RQS Easy Roots to enhance nutrient uptake and complement the peat moss microbes.

Taking the extra step of adding a nutrient supplement, such as the RQS Easy Combo Booster Pack, will provide your plants will all the minerals they need throughout the vegetative and flowering phases.

Once your seeds have grown into seedlings and outgrown their starter pots or plugs, transplant them into the peat moss mix.


Now, let’s round up a list of advantages and disadvantages to using these substrates. Each has proven its effectiveness in specific grow setups, although they may not be effective for every operation. Use the list below to help guide you.



Cultivating cannabis in coco coir is pretty uncomplicated and just like any other grow op; once you have your system dialled in, it’s plain sailing. ‘Nuff said.


Being oxygen-rich and an excellently water-retaining medium makes coco coir a really great habitat for cannabis plants’ roots. In addition, coco coir retains phosphorus very well and combined with the aforementioned attributes roots will positively thrive.


Coco coir is a natural product and a totally reusable. In fact, by growing ganja with coco coir you are recycling and putting to good use what would have been wasted coconut husk left to rot and pile up like trash.


If you want to keep your growing activities stealthy and delivery costs to a minimum, coco bricks are an elegant solution. A couple of 6 packs of coco coir bricks is feather light in comparison to lugging two 50l bags of soil home from the grow store. Also, should you choose to have coco bricks delivered, they will incur far lower delivery charges and less attention than heavy sacks of soil. Perlite to mix with the coco coir can be discreetly sourced from the local garden centre.


Root rot and nasty root invading fungi and insects are far less likely to plague the coco coir grower. Coco coir is nice and sterile and so well aerated, the roots develop almost as quickly as in advanced hydroponic setups.


The only real disadvantage of coco coir is if you happen to mistakenly buy a low-quality brick, that may have been incorrectly processed or somehow contaminated. This is rare and if you stick with reputable high-quality coco coir brands you won’t have to worry about this kind of problem. It really comes down to grower preference which way to cultivate cannabis. If you ask us, you really can’t go wrong with coco coir.



Peat moss works to cultivate a healthy community of microorganisms. Advances in the understanding of soil science have made it apparent that a diverse community of fungi and bacteria play a fundamental role in the health of the root zone. These organisms help to break down organic matter and make nutrients more available to roots. Fortunately, peat moss contains its own array of beneficial microbes.


Peat moss boasts clean and resistant properties. The growing medium is void of seeds, pest insect species, and pathogens. This trait makes it a risk-free soil amendment that will keep your growing medium free of invasive weeds and damaging critters.


Soil pH is a common reason for nutrient deficiency in plants. Even if minerals are abundant in the soil, the roots won’t be able to access them if pH is outside the required range. Soil-grown cannabis thrives in a pH between 6–7. If your soil is too alkaline, peat moss will help to balance things out.


Peat moss can help growers reduce their water usage. The substance is capable of holding up to 20 times its own weight in water. This makes it extremely economical, and especially useful in dry and drought-prone regions. Although damp soils can sometimes lead to mould and root rot, the aeration provided by perlite will help to counteract these threats.


Peat moss is a source of several nutrients that are beneficial for cannabis. One of the most prominent among them is sulphur. This essential mineral helps to form key enzymes and build proteins. Sulphur is also used in the creation of terpenes and may enhance the flavour and taste of cannabis flowers.



One downside to using peat moss as a soil amendment is that it requires a rather lengthy preparation process. If you’re growing outdoors, you will need to start preparing it in early spring so it’s ready for the growing season.


Industries commercially mine and harvest peat moss from naturally occurring peat bogs. This can sustain a substantial impact on this natural environment, which often has to be restored and repaired.


The water-holding ability of peat moss can make it extremely damp. The surrounding soil can squash the substance together, which leads to compact soil void of air. This is a recipe for root rot and air-starved roots. However, this is only a problem when growers use peat moss in isolation—additives like perlite can help to maintain adequate aeration.

Your cannabis growing medium isn't just limited to soil. Learn to grow the herb using coco coir and peat moss mixes.

Tips for Growing Autoflowers in Coco Coir

Coco coir (also known as coco fiber) is an organic medium extracted from the outer layer of coconuts, it is primarily known for absorbing and retaining water better than any other medium, you can find it pre-mixed with nutrients or amend it yourself, mix it with additives (like perlite or soil). To help you choose what suits you the best, we’ve separated a couple of tips.

1. The Qualities of Coco Coir

Coco is a very good medium to use, thanks to it being fibrous and strong, it resists weathering, can be reused, holds onto water and nutrients and has a light texture, so it provides a good amount of oxygen to the roots.

2. What Types of Coco I Can Find?

Coco may come in loose fibers or compressed in a brick, quality is usually the same although sometimes depending on the brand it may be stronger or more brittle.

Coco in a Brick

Usually, people buying coco fiber in a brick are looking to save space and a couple of bucks. It’s cheaper because you have a bit of work before using it and it saves up space because it comes compressed into a brick.

Tip: We recommend to bake it in the oven for a minimum of 4hs (up to 6hs) at 95 Celsius (203F) to kill any bug eggs left in it.

After letting it cool down, you have to immerse the whole brick in a big tub of water (25L, about 6.6 gal), you can use a mix of water and 10% bleach, but if you already used the oven technique, it may be an overkill.

Loose Coco

With loose coco you’ll spend a little bit more but you can skip the oven, it’s ready to use out the bag.

If you can’t find a good brand and you want to be 100% sure it’s clean, you could do the following:

Tip: Rinse coco to remove dust, if you suspect there are bugs in it, you can leave the fibers for a couple of hours in a tub with a mix of water and 10% bleach, it’s important to rinse them thoroughly with water only and then let them dry overnight, you don’t want to hurt your plants with any bleach left.

3. Choosing the Right Type: Inert or Amended

Inert Coco

Coco coir mostly comes inert, which means it does not have any nutrients in it, although you can find a wide variety of amended coco, and it definitely will ease your work, it comes pre-mixed so you cannot control the quantities and will not always be the best choice.

Amended Coco

If you’re going to use amended coco we recommend testing it before or go for a low level of NPK and feed after if you see your plant is getting hungry.

For best results, you should buy inert fiber and mix with a powder nutrient mix of your choice, this way you can control the quantity of every single nutrient your plant will have access to.

We recommend organic feeding, you’ll have a happier plant with an overall better harvest, generally producing more terpenes. You will taste the difference!

Always keep in mind that you will have to adjust the quantities to be used with your autoflower. Nutrients generally come with instructions to be used with photoperiods. An excess of inorganic nutrients in the medium can burn the plant (compromising your harvest) or end up killing it.

An excess of organic nutrients will not kill your plant but you’ll be spending way more than you should.

4. Different Types Of Additives

Before talking about additives, we need to talk about our climate. Being indoors or outdoor, our relative humidity should be around 60% and temperatures should be between 20 – 25 degrees Celsius (around 68 – 75 F). Obviously, that’s a general rule and may depend from strain to strain.

If our climate is not good enough we could have problems like our medium drying too quickly, holding too much water or roots not receiving enough oxygen. To achieve a good mix, we should learn about the qualities and characteristics of additives. A perfect medium should be fluffy enough for the roots to get oxygen but also hold a good amount of water.

Tip: To have 100% clean additives, we recommend rinsing with water and letting dry before using.


Perlite means small balls made mostly of silicon. It is porous and should be used if you are watering too much, they’ll help protect you against mold and will keep the medium oxygenated.

Tip: Perlite can be washed and reused for several harvests.


Soil + coco is usually mixed when you want to use pre-amended soil but need to hold more moisture. We recommend a mix of 50/50 soil to coco and adjust according to your preferences. You can mix amended soil or inert, also can mix your own mix of powdered nutrients to the inert soil of your preference.

5. Watering and Feeding

When watering coco, you should never let it dry out, try to keep the medium always slightly wet or at least damp. Usually, you’ll need to water up to 4 times a day in coco, depending on climate and stage the plant is in. When feeding inorganic, mix nutes with water, adjust pH and water.

If you’re using a top dressing or you already mixed nutrients in the medium just water, you don’t need to feed unless the plant is hungry. With organic feeding you don’t need to adjust pH, just mix nutes and water normally, if you’re using a top dressing or already have nutes mixed in soil only feed if the plant is hungry.

Tip: Try to use osmosis water or at least filtered water when feeding inorganic to you autoflower.

6. Different Medium Mixes

Here we leave a couple of recipes for different cases:

• General mix recipe: 30% coco, 20% perlite and 50% soil or 80% coco to 20% perlite.

• For a well-drained medium: 70% soil to 30% perlite.

• For a well-aerated medium: 80% coco to 20% perlite.

• If your soil is drying too quickly: 70% soil to 30% coco.

3. In Conclusion

You need to remember not all plants are the same, there can be variations even in plants of the same strain. We recommend knowing each individual plant to deliver the optimal mix of nutrients and soil but like everything, there are exceptions.

Sometimes you’ll find plants that do well without nutrients, that’s the case of our Purple Lemonade, a cross between Purple and our citrus Cali genetics.

Coco coir (also known as coco fiber) is an organic medium extracted from the outer layer of coconuts, it is primarily known for absorbing and retaining water be ]]>