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.
WHAT IS COCO COIR?
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.
HOW TO GROW MARIJUANA IN COCO COIR
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.
HOW TO FEED CANNABIS CULTIVATED IN COCO COIR
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.
HOW TO GROW CANNABIS IN PEAT MOSS
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.
PROS AND CONS OF COCO COIR AND PEAT MOSS
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.
ADVANTAGES OF COCO COIR
LESS STRESS MORE SUCCESS
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.
100% ECOFRIENDLY AND REUSEABLE
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.
LIGHT WEIGHT AND COVERT
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.
LESS VULNERABLE TO INSECTS AND PLAGUES
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.
DISADVANTAGES OF COCO COIR
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.
ADVANTAGES OF PEAT MOSS
ENHANCES SOIL HEALTH
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.
FREE OF COMPETITION AND CONTAMINANTS
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.
HELPS TO ACIDIFY THE SOIL
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.
EFFECTIVE AT RETAINING WATER
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.
CONTAINS KEY NUTRIENTS
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.
CONS OF PEAT MOSS
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.
CAN BE ENVIRONMENTALLY UNSUSTAINABLE
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.
CAN LEAD TO COMPRESSED SOIL
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.
Coco Coir: The Most Flexible Cannabis Grow Medium
Coco coir (often referred to simply as “coco”) is the most flexible grow medium. Made out of coconut shells that would otherwise be thrown away, this unique substance has surprising benefits for cannabis plants.
Coco coir is made of coconut husks that have been ground up. It is often sold as compressed bricks for easy shipping and storage.
When water is added, it slowly expands into a substance that looks like pale soil
Pure coco coir after it’s been rehydrated
Many growers add up to 50% perlite (airy white rocks) to loosen the coco and create air pockets that help plants grow faster.
Cannabis plants thrive in coco in a variety of setups
Coco produces excellent bud quality! I grew all these buds in coco coir.
Pros of Coco Coir
- No Bugs – Plants are much less likely to get bugs in coco than growing in soil because the material is inert. Many bugs need soil as part of their life cycle. It’s possible to get bugs in bad conditions such as extreme overwatering (which can result in fungus gnats), but coco bug infestations are unlikely in regular conditions.
- Doesn’t Stink – Regular potting soil has a pretty mild earthy smell, but most “just add water” soils contain stinky amendments like guano which can make your grow room smell foul. On the flip side, coco has basically no smell.
- Fast Growth – Coco plants have the potential to grow faster than soil with certain techniques. As fast as hydroponic plants in some setups.
- Precise Nutrient Control – Coco offers total control over nutrient ratios and nutrient strength. Perfect for growers who like being involved with their plants.
- Friendly to Environment – Coco is a renewable resource that would otherwise be thrown away.
- Learning – Growing in coco is a lot like soil when it comes to watering, yet a lot like hydro when it comes to nutrients. As a result, growing in coco prepares you for both soil and hydro growing if you decide to try something else in the future.
- Flexibility – Coco can be used in many different ways with great results. There’s more room for experimentation than with soil or hydro.
Cons of Coco Coir
- Needs Nutrients – Coco does not contain any nutrients on its own, so you must add nutrients in the water for healthy growth. While mixing up nutrients is fun and exciting for some growers, others find the process too complicated or time-consuming.
- Environmental Concerns – Coco itself is excellent for the environment, especially when using pure coco and only a moderate amount of nutrients. However, coco potting mixes often contain perlite, a non-renewable resource made of expanded volcanic glass (then again, most soil mixes also contain perlite). Some growers have started replacing perlite with environmentally friendly rice hulls , though I haven’t tried that yet. Additionally, if you’re using tons of nutrients (for example with a high-frequency fertigation schedule, discussed below), you may have to dispose of a lot of nutrient water runoff. Dumping nutrient-filled water into our water system isn’t great for the environment.
- Room for Error – Ultimately, coco creates more judgment calls than soil. There isn’t a nutrient buffer like in soil to help make up for mistakes when giving nutrients. It’s important to follow directions for the best results with coco. If you’re looking for the simplest way to grow, a “just add water” soil might be a better choice.
The coco plants I’m growing right now in Mother Earth Coco + Perlite Mix with the Flora trio + CaliMagic as nutrients (here’s my nutrient schedule). These plants have been in the flowering stage (on 12/12) for only 19 days and look at all those buds already!
Ways to Use Coco
As an Amendment – mix coco into actual soil as an amendment
- Coco can be added to regular soil to improve its quality
- Coco is better for the environment than non-renewable peat moss (which is what coco usually replaces in a soil recipe) and works better for growing cannabis
For example, Coco Loco is a soil that contains coco instead of peat moss. I’ve found Coco Loco is one of the easiest grow mediums to start cannabis plants in. In my experience, young plants and seedlings seem to grow faster in Coco Loco than popular peat-based soils like Happy Frog or Ocean Forest. Coco Loco is a great option with a good mix of the benefits of both coco and soil.
Coco Loco is a mix of soil and coco. Get the best of both worlds!
Treat Coco Like Soil – water every few days with nutrient water
When using pure coco or a coco/perlite mix, you can treat it basically like soil as long as you’re giving nutrients in the water.
- Efficient nutrient use
- Less time mixing nutrients
- Little nutrient water runoff to dispose of (better for the environment)
- Use bigger pots to w ater less often
- Learn how to grow cannabis this way
Mother Earth Coco + Perlite Mix can be used straight out of the bag. Just add plants and give coco-friendly nutrients! I’ve had excellent results with this brand.
Treat Coco Like Hydro – high-frequency fertigation, drip feeds, or flood-and-drain
In these types of setups, the coco is mainly there to anchor your roots while you treat the plants like they’re in a hydroponic setup.
- Fastest growth
- Frequent watering
- As often as multiple times a day
- Best to set up automatic watering on a timer
- Watch out for fungus gnats and droopiness from too-wet conditions (fix these issues by watering less at a time or less often until plants are drinking more)
- Use smaller pots and always add perlite to coco to prevent droopiness as well as get more oxygen to roots
Flood & Drain systems may use coco to anchor the plant roots. Nutrient water “floods” the plant roots multiple times via a timer and then drains. This combination gives roots a constant flow of both nutrient water and oxygen. These systems can be tough to get set up yet produce surprisingly fast growth once dialed in.
High-frequency fertigation and drip feed setups are similar. However, instead of nutrient water getting pumped in like a flood, it’s dripped to the plants via tubing.
In a traditional drip system, runoff water is pumped back into the main reservoir to be reused. However, the quality of the nutrient water goes down over time as plants use up nutrients.
To ensure plants are getting fresh nutrient water each time, the runoff water may be collected and disposed of (instead of putting runoff back into the system to be re-used)
- Anything in between
- Experimenting is fun
- Get a mix of benefits!
What is high-frequency fertigation?
Fertigation means adding nutrients to the water you give to your cannabis plants. Cannabis plants typically grow faster when they get nutrients from the water as opposed to seeking out nutrients in soil. When cannabis growers talk about fertigation, they’re often referrin g to high-frequency fertigation, which means watering plants w ith nutrient water frequently.
High-frequency fertigation means giving nutrient water to cannabis plants as often as 5x a day. When set up properly, marijuana plants typically grow faster in high-frequency fertigation than plants watered a few times a week.
Give water multiple times a day by using drip-lines that pump nutrient water to plants on a timer
High-frequency fertigation must use a grow medium that contains air pockets even when wet to prevent roots “drowning” from lack of oxygen. The most popular grow medium for high-frequency fertigation for cannabis is a coco + perlite potting mix (another option is clay pebbles/hydroton, which can handle watering even more often than coco).
In this grow style, cannabis plants are usually given nutrient water automatically on a timer via an automated drip-feed. Automatic irrigation will save a ton of time compared to hand-watering multiple times a day!
- use well-draining potting mix (50/50 coco/perlite works well)
- use hydro or coco-specific nutrients (such as Canna Coco or Flora Trio)
- for more frequent fertigation, use smaller pots
- get an automatic watering system (you will forget if you try to hand-water!)
- give nutrients every watering
- try to ensure EC/PPM of water going in and out are about the same
- if plants look perpetually droopy give water less often or less water at a time until plants are drinking more
- maintain 5.5-6.5 pH of the water
- always remove runoff water or have it drain away (never let plants sit in runoff water).
Bonus tip: Your growing medium is important, but the secret to amazing bud quality is actually a combination of two other things… You must choose the right strain and give plants a great environment in the flowering stage.
Don’t ignore temperature or humidity problems when plants are making buds! As long as plants are healthy, the flowering environment determines whether genetics live up to their full potential.
And remember that regardless of anything else you do, you can’t grow outstanding buds without great genetics!
Check out American genetics for extra sparkly strain options!
Coco Coir: The Most Flexible Cannabis Grow Medium Coco coir (often referred to simply as “coco”) is the most flexible grow medium. Made out of coconut shells that would otherwise be thrown away,