growing cannabis in 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.

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

How To Grow Cannabis in Coco Coir

Coco coir has made a name for itself as a growing medium in the cultivation scene. Now widely used by growers, people have realised the benefits of using coco coir for its ability to provide roots with the perfect home they need, to give cannabis plants the life they deserve!

You may have heard of coco coir but still have no idea how it can be used for cultivating cannabis. Coco coir is a highly effective substrate that is actually very straightforward to use. We’ve created this guide to give you some top tips on how to get started with coco coir.

Coco Coir: What Is It?

Coco coir is made by grinding up coconut seed husks. This results in an inert growing medium that is light and has a texture similar to that of soil, but acts in different ways. Coir is extremely versatile and is especially good for cultivating cannabis.

Coir, also know as coco peat or simply coco, is almost completely free of nutrients. Apart from the phosphorous and potassium naturally present, it provides nearly no nutrition to cannabis plants.

Why Grow Cannabis Using Coco Coir?

Before we get started, let’s take a look at why using coco coir is so good for growing cannabis. Coco coir acts like a hydroponic substrate but is often used with or instead of soil to improve aeration and water retention.

There are many advantages to using coco coir if used in the correct way. Whether you are growing in the ground, with pots or hydroponics, coco fibres can improve your garden significantly.

  • Adequate Drainage – Because of its fibrous nature, coco coir drains water particularly well, reducing the risk of overwatering.
  • Water Retention – Even with effective drainage it still manages to hold enough water content to keep roots hydrated.
  • pH Neutral – Has an optimum pH level of 5.6 – 6.2, the ideal range for cannabis cultivation.
  • Effective Aeration – Coco coir has a light, airy structure which allows for plenty of oxygen circulation around the root zone.
  • Eco-friendly – Coconut husks are a natural, renewable resource that can be recycled 2 – 3 times for growing.
  • Affordable – Cheap compared to high quality soils or other mediums such as peat moss.
  • Less Pests Than Soil – Using coco as a substrate provides roots with an inert environment which does not attract many pests or harmful bacteria.

Types of Coco Coir

The structure of coco coir depends on how it is processed. Coco fibre is often compressed and bought in blocks which are rehydrated when they are ready to use. Coco coir can also be purchased uncompressed in bags.

Fibre – Coco fibre is stringy and comes from earlier stages of coconut husk processing. Usually compressed into a block. Provides improved space for aeration but does not absorb much water.

Chips – Chips are chunky pieces of coco husk that have the benefits of both fibre and pith coir. Coco chips allow for healthy levels of oxygen movement around roots, as well as retaining enough water.

Pith – Pith coir is probably the most similar to soil in terms of its texture. It can be compared to peat moss but is brown in colour. Pith coir holds more water than other types of coco, reducing oxygen flow.

Tip: Coir works very well as mulch for indoor or outdoor gardens to help protect your top soil.

Growing Cannabis In Coco Coir

Preparing Your Substrate

There are many ways coco fibres can be used with other mediums or amendments to create the perfect substrate for your cannabis. The first step with coco usually involves rehydrating and rinsing.

Buying coco in a compressed form will require you to break it apart in a pot/bucket with warm water and let it sit for a while to soak. Start with small amounts of water and add more until it becomes fluffy and fibrous. When it’s ready it should be moist and light, not completely drenched and heavy.

Buffering the coco coir with a calcium/magnesium solution after it has been rinsed is advised. This is because calcium and magnesium are absorbed quickly by the coco fibres before plants get a chance to use it, leading to deficiencies early on.

Coco coir can be mixed with soil to improve aeration and drainage. If you want to use it as an alternative to potting soil, we recommended that you mix it with perlite. Always check the quality of your coir before purchasing to make sure it does not contain any chemicals or other harmful by-products like high salt concentration.

A well mixed coco substrate should contain at least 10 – 15% perlite . Although on the expensive side, there are pre-mixed bags of coco coir available to buy which already contain perlite, saving you some steps.

Cannabis plants in pots benefit from a 2 – 3 inch layer of clay pebbles at the bottom of containers to aid oxygenation and drainage. Pots can then be filled with your preferred coco coir blend.

Nutrients For Coco Coir

The fibrous structure of coco coir is a perfect home for the development of beneficial microorganisms. Since there is almost no nutritional value in coco, we must provide the required minerals ourselves. There are nutrients designed specifically for coco coir, however most liquid nutrients for hydroponics can be added without issues.

Organic fertilizers can also be used in coco coir, but overall growth may be slower. Either way, proper feeding should start in the seedling cycle once cannabis plants have 2 – 4 sets of leaves.

Check the guidelines on the nutrient bottles, but start with half strength and work your way up with each feeding if plants need it.

This is where you need to decide how much your plants are consuming and adjust accordingly. If they are growing slowly or showing signs of deficiency, you might need to up your regime if you have been giving low doses. Just make sure you do not over feed your cannabis plants. Watering more regularly with lower levels of nutrients is recommended. If possible, try to get into the habit of giving enough water to last plants a day or two.

Most store bought cannabis fertilizers will contain the necessary NPK levels, as well as some added micronutrients. Normally, brands offer different bottles for each stage of growth. In this sense, it’s good to stick with one brand for consistency and compatibility of nutrients.

Nutrients for growing in coco coir:

  • Root stimulators – Supplements to aid development of rhizobacteria around roots can be used until the flowering cycle.
  • Nitrogen – Very important for the early stages of foliage and plant growth. Less important for bud production during flowering.
  • Potassium and Phosphorous – Already present in coco coir, but should be readily available throughout the grow cycle. Plants benefit from higher concentrations in bloom.
  • Micronutrients – Although not always essential, trace minerals such as copper, manganese, zinc, boron, and molybdenum are usually mixed into cannabis liquid solutions.
  • Calcium – Deficiency is common when growing with coco coir. Cal – Mag (calcium/magnesium) can be added during vegging, reducing the dosage with watering until the early stages of flowering.

You can get an idea of how some of these important minerals are absorbed at varying pH levels:

This post teaches you all about coco coir. Discover how to grow cannabis in a wonderful inert medium made from coconuts.