How to Grow Cannabis in CocoNovember 29, 2018
Coco coir is seen as one of the best grow mediums you can use to grow many plants, not just to grow cannabis. It is light, low density, has great drainage and allows plenty of air to get to the roots. This is why many growers grow cannabis in coco.
Because of how good the drainage is, it is very hard to over water in coco. The water will run straight through the medium, pulling air with it, and moistening the medium as is passes through. This give the roots a great ratio of air and water, which means the plant will eat more. The more they eat, the bigger and faster they will grow.
Coco is also void of nutrients, so you can control exactly what your plant is eating. You will know exactly what is in the medium and available to your plant as food. You have a massive amount of control over your plants diet when growing in coco. So deficiencies are easy to fix if they arise.
What Nutrients to Use to Grow Cannabis in Coco
There is a huge range of different brands that make cannabis nutrients. It is not easy to say which one is the best. Each one has certain pros and cons. It is best to go with a brand that has a good reputation for producing quality plants.
See our guide on the best nutrients for growing cannabis in coco:
How to Prepare Coco for Growing
Let’s begin on how to prepare your coco. Some companies will wash their coco with salt waters and other contaminants that you do not want in your grow medium. It is always best to wash the coco well, before putting it into your pots.
Fill the pots you intend to use with coco straight out of the bag. This will give you an idea of how much coco you’re going to have to prepare. Empty that coco into a large container, and fill it with warm water.
The coco will be floating around the top of the water, get your hands in there, give the coco a good rinse, and let is stand for five minutes.
Now you need to filter the coco. The lighter the coco is, the better the drainage and air flow in the medium will be. So you need to remove the smaller bits of silt and grit.
By rinsing your coco through a sieve, or colander, you can remove all the smaller bits, and keep the bigger coconut fibres. This will improve the drainage and aeration of the coco.
After the coco is well rinsed, filtered, and clean, you can put it in your pots. Now, it is time to balance the pH of the medium.
How to Balance the PH of Coco
Prepare some warm water, and pH it to 5.8. You will want at least three times water as you have pot size. If you have a 2 litre pot, you will need 6L of water to prepare at 5.8.
Pour the pH’d water slowly through the medium in the pots. If the coco washes down, just rinse some more coco, and add it to the top. Then continue to water with your pH’d water again, until the coco stop sinking.
Once you have washed all of your pH’d water through the coco, the medium should sit at a happy 5.8. and will now be ready for seeds to be planted into.
Coco Feeding Schedule
If there is too much food, the plant will stop eating as the roots will get clogged with salt build up. Not enough food, and the plant will not grow to it’s full potential, and could be at increased risk of bugs and diseases.
It can seem like a bit of a science at first. It is just routine, and small incremental changes as the plants grow. Stick to these feeding rules when you’re growing cannabis in coco, and you will never have an issue.
EC & pH in Coco
You have to know you background EC ( the EC of your water before any food or additive is added). Let’s say for example it reads 0.2 on your EC meter. This number will always be counted into your final EC, as it will make up part of the available minerals your plant can eat.
Young plants will do well, with a EC, just 0.2 point above your BG EC, so in this case 0.4 ec. This will give a small amount of food to the plant, and you can monitor the amount it has eaten from there.
As the plant grows, it will start to lose the healthy green and go a little pale, this is when you need to up the EC again by 0.2 point, making it to 0.6 in this case. Steadily increasing the EC like this will give the plant a steady increase of available food.
Don’t over do it. Watch the plants colour, if they are pale, they need food, if they’re too dark, they need less. Plant Problems are easy to fix when you grow cannabis in coco.
Do Not Over Feed!!
The only time you will give your plant fresh water, with no food in, is when you are flushing. Coco needs to be fed, everyday, to keep the medium fresh, and making sure there is plenty of fresh food for the plant to eat.
If your plant is receiving more food than it can eat, you can run the risk of causing a salt build up. A salt build up will not only stop the plant from eating, but will also affect the PH of the medium, and the plant will stop eating the right food. It won’t take long before the plant begins to suffer, and deficiencies will form.
To prevent this, always keep the EC low, and make sure you have at least 10% run off with every feed, and drain the runoff away. Do not let your plant sit in it, or re-use it. The salts in that liquid are old and not good for the plant, it needs to be removed. Removing runoff is very important when growing cannabis in coco!
Testing Your Run Off When You Grow Cannabis in Coco
Another way you can tell if you’re over feeding your plant, if by testing the run off. The run off coming out of the medium need to be the same as it went in, or no more than 0.2 points lower. If it comes out too high, it means the plant is not eating everything from its last feed. The old salts are building up in the medium, and getting washed out with the water. This is a clear sign you are over feeding, and you should reduce your ec right away.
If the ec comes out much higher than 0.2 point, you will need to flush the medium to restore the levels to optimal.
To do this you will need 3x water as you have pot size, for example. 5l pots, should be flushed with 15l of water. The water should have no food in it, and should be ph’ed to 5.8.
Once the flush is complete and all run off has been removed, you will feed your plant again, at a lower EC than the last feed, and PH of 5.8 to restore the correct levels to the medium.
It is that easy. If you ever have any problems growing cannabis in coco, it can be solved in less than 24 hours. Usually after a good flush, to restore the PH and the EC, of the medium, a plant will pick right back up. If it doesn’t, the issue may lie elsewhere, and you should consider asking for help in our cannabis growers forum.
Do Not Let the Pots Dry Out
As water evaporates, salts will be left behind. The salts are dissolved in the water, and when the water leaves the medium, they stay in the medium.
If you feed your plant at a high EC, you need to make sure the medium stay moist! If it dries out, the medium will have an EC spike, which will affect the plants.
Coco should be watered daily to keep the pH and EC in balance. If you do not have time to water daily, consider using an auto feeding system, or feed at a lower EC, to compensate for the EC spike when the medium dries out.
Final notes on growing Cannabis in Coco
Keeping the medium balanced is a massive part of the battle to keeping a happy healthy cannabis plant. Monitoring the run off, and keeping the feed low, with gradual increases, will see that your plant is always sitting in a great root zone.
Thanks for reading! You can find more information on anything related to growing in our cannabis grow guides. All of our guides are written by experienced growers, and members of our cannabis growers forum. If you have any questions, sign up. It is free, and we are always happy to help!
Good Luck with your grow! Stay safe, and Happy Growing