May 28, 2019

A Guide to Cannabis Growing in Coco Coir

May 28, 2019
Grow great cannabis with Coco Coir.

What is Coco Coir?

Coco Coir soil is a waste product made from the husk of coconuts, primarily from those found in the Philippines, India, and Sri Lanka. This material was simply discarded until some clever and aspiring cultivator discovered its amazing properties as a “grow medium” for both indoor and outdoor plants. Coco Coir can be bought in shops, generally in three different size options: 25 pounds, 50 pounds, or a small compressed brick. 

Brick Coco Coir is what I like to use personally, as the little brick stores away much easier than the hefty bags until ready for use. To use the brick, simply place it in a large bucket or a sink with 4-5 liters of water that has a pH balance of 5.8 to 6.2. Let it soak until the fibers start to expand and come apart. Once soft, the brick will break apart easily, and all you need to do is add two to three liters of perlite and mix with your hands. Now you’re ready to grow!

Coco Coir pH level /pH for Coco Coir Soil Mix

Because Coco Coir is a material derived from coconuts, it generally has a pH balance between 6.5 and 6.7, which is equivalent to that of natural soil. Coco Coirsoil allows some forgiveness when it comes to pH fluctuations, but growing with a proper pH meter is necessary so you can keep your water/nutrient mix between 5.9 and 6.1, which provides an adequate nutrient uptake for the pot plants. 

It’s imperative that you don’t cheap out on the Coco Coir product. Buying the best quality is in the best interest of your experience as a grower and also of your marijuana plants. Lower quality Coco Coir is known to have higher salt contents that can cause all kinds of problems for any strain of marijuana you are growing. However, if you do purchase cheap Coco Coir, we recommend washing it in pH corrected water first. This will change the pH level in the Coco Coir back to the 6.5 – 6.7 level which is ideal for growing cannabis plants. 

Coco Coir Nutrients/Best Nutrients for Coco Coir Grow

After researching how to grow cannabis in Coco Coir, I found that many cultivators are in the practice of mixing certain soil with the (Coco Coir) to create a super soil mix that maximizes the growth potential of the marijuana plants. This means bigger buds, which translates to a bigger yield. But, wouldn’t you also think using 100% coir would be better than diluting it with soil? No, not exactly. 

If you aren’t using Coco Coir specific nutrients, you will almost certainly run into a few difficulties you will need to correct for. As amazing as the product is, Coco Coirsoil cannot hold calcium efficiently, necessitating increased calcium and magnesium supplements. Add those supplements to your water supply, though, and you will be in the clear. Boosting your Cal/Mag supplements to about 15% should help you avoid most of these issues. You could also run into a problem with deficient iron intake, which would also need to be supplemented. Just be sure to test your soil’s nutrient levels to know exactly what you need. 

Best Fertilizer for Coco Coir

Any grower can easily make the transition from standard soil to Coco Coir. Generally, liquid nutrients, such as those found in multi-solution fertilizer systems, will work best for growing in Coco Coir, but some soil specific nutrients will work as well! Coco Coir is different from soil in that it contains lower naturally occurring base nutrients. This means that your Coco Coir will need significant levels of nutrient solution from day one until your final two weeks of flowering.

When it comes to feeding your plants, Coco Coir is no different than dealing with plants in soil. If the top inch of the Coco Coir is dry to the finger and the pot is getting light, it’s time to water.

Learn how EM-1 can help enhance your yields within weeks.

The Benefits To Growing Cannabis in Coco Coir

As a cannabis enthusiast first starting to grow, I ignored advice about using substrates other than soil. I thought, if it was good enough for Mother Earth, it’s good enough for my weed. 

It wasn’t until I went to visit a medical cultivation facility, run by a friend who had made growing his lifestyle, that I witnessed the measurable difference between cannabis grown in soil and cannabis grown in a substrate known as Coco Coir. That day, I had my third eye pried open to the massive potential of growing in Coco Coir soil. 

What Are Some Advantages of Using Coco Coir as a Grow Medium?

In general, Coco Coi) is a forgiving and easy to grow medium once you have a system that works. If you start with the proper water and nutrients, you really shouldn’t have any unexpected issues with the way things are growing. Coco Coir has many advantages to using it as a grow medium, these are just a few examples of why it’s a fantastic option:


Coco Coir is a natural byproduct of coconut and nothing more than husk fiber. So, when you purchase Coco Coir, it’s already the second use of the material. A safe rule of thumb is you can use the Coco Coir around three times before you should put it out to pasture as mulch. The Coco Coir fibers will start to break down over time, so it’s best to retire it before it starts to lose its structure.

Fewer Insect Infestations

Unfortunately, more than once, I’ve brought home a bag of potting soil that just happened to be infested with spider mite eggs. It wouldn’t be until about a month into the growing process when I started to notice pests such as spider mites and whiteflies. Though they appeared shortly after I brought the soil home, make no mistake that these pests came with the soil. This is not an issue you have to worry about with Coco Coir, as its material is resistant to root rot, fungi, and insects. 

Growth Improvements

There is no doubting the benefits of Coco Coir after you notice the remarkable difference in growth. You’ll notice better, faster vegetation right away because of the useful water/nutrient management Coco Coir provides. That extra oxygen in the roots coupled with having more water/nutrients in contact with the root system increases plant growth and health which provides both a larger harvest and some truly dank product.

Tips for Growing in Coco Coir

The primary tip we have when using Coco Coir is to avoid using plastic or ceramic pots for growing cannabis. A significantly better option here is to use a fabric pot, which further allows oxygen transfer from the atmosphere to the root system by way of the air pockets from the Coco coir.

Coco Coir FAQs: 

Is Coco Coir Better Than Soil?

Coco Coir has a one-of-a-kind attribute: its ability to hold water while still providing the millions of tiny oxygen pockets within the root system of the marijuana plants to breathe. This makes it notably dissimilar from standard soil, which needs to dry out almost completely between feeds to ensure there is oxygenation. 

Another reason Coco Coir is a great grow medium is that it retains the ability to hold phosphorus exceptionally well so that the plants will yield larger buds.

What Can You Add to Coco Coir?

While Coco Coir does contain some level of basic nutrients, if you’ll be growing cannabis with it, you’ll need to fortify your grow with a proper cannabis nutrient combination.

To truly get the best results with Coco Coir, it is recommended to mix it with 20 to 30 percent Perlite so you increase the air space in the root area. Perlite is a volcanic glass that allows water to be trapped inside its structure, further increasing the substrate’s ability to hold water for longer periods of time.

How Many Times Can You Reuse Coco Coir?

Coco Coir isn’t recycled just once; you can use it up to three times before the fibers start to decompose. After each grow, you’ll need to rinse the Coir fiber very thoroughly with water that has a pH balance between 5.8 and 6.2. This wash of the substrate will remove any mineral and fertilizer salts from the fiber, allowing for maximum potential of growth.  

How do I Test My Coco Ph and Raise as Needed?

There are nutrient blends ready for sale with pH balanced perfectly. Even so, you’ll still need a pH meter which will verify the water pH level before the nutrients are added. To measure the pH of your water, you’ll use a pH meter, a bottle of pH Up, and a bottle of pH Down. 

Check the water’s pH with the meter, and if the water is too alkaline, you should add a tiny bit of pH Up. But, if the water is acidic, add a little pH Down and check with your meter again. Follow this process until your water is in that 5.9 to 6.1 range.

Don’t be Afraid to Expand your Knowledge

I’m satisfied with the average results of the way things grow. Making changes to your growing procedures brings risk to your crop, and normally I am not a fan of taking this sort of risk. However, you’ll never achieve that otherworldly dank harvest without taking a few calculated risks, and taking a risk with Coco Coir has certainly paid off for me. 

Coco Coir represents a choice alternative growing medium in cannabis cultivation. There are variances and procedures to learn to be successful with this substance, but that little bit of studying will set you far ahead of beginner level cannabis cultivation.

Additional Readings on Cultivation

The Weed Blog: a place to find reviews of certain top strains of cannabis and online news resources regarding the legalization of marijuana. We are committed to helping you find valuable information about cannabis activism on our website. With the laws of marijuana constantly changing, learn about the latest legislative and statutory changes on our website and what you can do to make a difference. Otherwise, consider these other top tier articles regarding cannabis cultivation:

What Is The Best PH And EC Levels For Hydro Marijuana Growers?

How To Grow Gigantic Marijuana Buds

Cannabis Cultivation Compliance And Management


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