The Budsman’s Guide to Growing With Coco (Part 1)

Budsman’s Guide to Growing Okay Stuff (Sometimes) *

** Disclaimer: The budsman does not claim to be qualified, or even have any real skill at this. These days I use expensive canna coco and nutrients, Reverse Osmosis water for 100% of every feed, as well as a daily test of the EC in and out, and it works for me. I hope you do learn something in these articles, however, and that this can perhaps be the beginning of your own personal journey; hopefully at least enough to survive a plant ’til chop. The discovery of the complex endocannabinoid system by medical science was a relatively recent one, but it has revolutionised the way we approach cannabis. We are still a long way from truly understanding “broad spectrum” cannabinoid treatments, and there’s a way to go before they can be used in predictable ways in their relationships with the hundreds of other cannabinoids and terpenes. Even still, the next couple of decades look very promising for growers, breeders and enthusiasts alike.*

With that said, let’s get into it.

Seeds, Strains and Buds

The Budsman recommends starting off with outdoor hardy, cheap mid type strains or expensive photoperiods that have been stability tested. I will rep Holy Smokes’ fem seeds hard and unashamedly until I get anything less from A+ results in terms of yield and quality and stability from their strains. I also recommended you check out Guide Dawg. Go to the man himself for quality, yield and consistency in your seeds. You can potentially ask around on instagram for who is carrying his seeds in Australia.

healthy roots = healthy plant = healthy buds

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This is a golden rule. If you’re not focusing on this in the vegetative phase, don’t expect the plant to magically bud up in flowers, no matter how much flower booster and light you throw its way. Although, being a weed, cannabis can bounce back stronger than ever from the right kind of beating.

For photoperiods or select autoflowers (such as Mephisto’s), be sure to treat ’em mean, and keep ’em keen in the vegetative stage. They can can take all kinds of plant torture. If you do it right, they just fucking throw big ass knuckly stems and buds back at you in retaliation. Not all of em are into that, though. It can also be easy to overtrain and snap plants, so do be careful about your plant abuse.

I personally recommend starting with photoperiods, as you usually stunt ’em pretty bad while getting the hang of things… not to mention any effects of a lacklustre or cheap setup.

Weak Links

Max. grams you can expect, relative to watts pulled from the wall:

  • HPS 1/W yield
  • Blurple/LED 1g/W yield
  • CMH ~ 1.5g/w yield
  • LED ~ 1.5-2g/W yield

To hit 2g/W, efficient light spread becomes very important. The quantum boards aren’t really that efficient, so expect closer to 1.5. Although they are improving each year at a staggering rate. Connecting up tonnes of HLG 100 boards can have the same effect in terms of increasing light spread efficiency, but it gets expensive.

Horizontal Space

You can expect most strains to cover 400-600g/m2. A lot of hype strains in particular can have a decent range of phenotypes. From any random seed, aim for 400g/m2, which equates to 300g. This is 10+ zips from a tent with a 4x2ft horizontal area packed out decently, which works great given the plant is provided with ideal conditions.

A 260W HLG light does a 4x2ft (8sqft or 0.75m2) space perfectly, as does a 315W CHM and a 400-600W HPS. That’ll let you grow from start to finish without a hitch. You then want to start hitting yield/W numbers in order to gauge how you did. Blurples aren’t all that great for flowering, but they make very good vegetation lights for the price. They can still grow great bud from up to 1g/W of wall juice, if you’re doing it right.


In terms of room temperature, 20-30 degrees is manageable. Genetics do vary, however, and the room/tent insulation/extraction can also help to optimise growth. It’s a good idea to keep a temperature and humidity sensor in your tent that records minimums and maximums continuously. You want to be turning over air in your space every 5 minutes. You want most of the leaves to be lightly rustling, as this maximises the CO2 that the leaves can absorb.

Vapour pressure and the genetics of your plant can be [more important] than simply the temperature or humidity in the room alone, so be sure not to put the blinders on! If your environment isn’t fairly well controlled, consider hardier, outdoor strains. You also want a nice even distribution of photosynthetically active radiation (PAR) across your canopy. To achieve this, be sure to set your EC in and out as the the same, and keep your pH around 6.

Fungus Knats, Spider Mites, Aphids: Oh My!

They love coco. The knats themselves are harmless, but the larvae they lay eat your roots… until they can hatch into flies. Numbers can build up very quickly, particularly if you mixed your soil in a garden with tonnes of them. Their flies can hatch all at once, which is pretty scary. Be careful of bringing other things into your growing operation. To get an idea of what’s flying around, sticky traps could come in handy. Another way to check is to closely examine the health of your leaves, checking for random little spots.

I prophylactically treat my coco with BTi, which acts as a kind of knat smack/mosquito dunk, because I can never avoid having the fuckers build up in late vegetation or early flower stage, otherwise.

In Warm Conditions:

The plants want higher humidity so they can retain water. Otherwise, they will start stressing. They’ll display this by the taco shape of their leaves, which serves to decrease the light intake of the leaf and slowing airflow to reduce evaporation. This generally happens on upper growth, where highest temperatures are reached.

Leaves in the middle look wrinkly and old if there’s not enough airflow and light. This is an Indica problem, and generally occurs because the canopy is too thick. Training your plants can help to reduce this.

In short, you want to increase the airflow on your canopy. You’ll need air conditioning, humidity domes, a dehumidifier, a mister using Reverse Osmosis water in vegetative stage, and other forms of extraction to keep your plants healthy in the heat. In particular, extraction at top of your tent, and intake on the floor, can assist with air circulation.

In Humid, Cool Conditions:

Cannabis plants love lower humidity for the same reasons they want high humidity at high temperatures. In some places, this makes a winter grow difficult, as humidity comes to these places with the cold. To counter this effect, you will need to defoliate the plants and increase airflow significantly. You’ll need dehumidifiers and temperature regulation that keeps the grow above 20 degrees in the daytime. This becomes even more important later in flowering stage. HPS shines in this regard, as it radiates heat very nicely.

Cool Temperatures With Low Humidity:

These are conditions you want your plant to flower in, generally speaking. If you’re facing these conditions, everyone else is jealous of you.

Seedling Stage

To germinate the seed, you can the soak it in water for 12 hours or so. It is all that important? Who knows, but I had one seed commit suicide from self decapitation by seed shell… so, I soak all of mine now.

From there, put it in between two plates in a damp towel. As soon as the seeds are beginning to germinate, place them into pots – a 4L pot from Bunnings will do. Using small containers will save you on water and nutrients. You can then move up as needed. Remember, pots can be re-used!

Be careful out there, as there are a lot of cheap/bad quality soils. Stuff like Bunnings Coco Coir will wash out at a really bad pH for a decent while, and actually charge more than other gardening stores.

VPD in Vegetation Stage

It’s recommended you follow the Vapour-Pressure Deficit, here, as the plants can handle higher temps and higher humidity. However, if you’re using VPD, you’ll have to make sure the airflow is particularly good. The carbon around a plant in stagnant air is used up for roughly 1cm around it every 10 seconds, so you want the leaves lightly dancing (using oscillating and/or clip on fans) with good air turnover in your tent. You’re aiming to replace the air in the tent every 2 to 5 minutes, with a carbon filter attached.

If you have a 180cm high tent (4×2 ft) you have 180cm (~6 ft). 6ft x 4ft x 2ft = 48 cubic feet of space – so in this case, you won’t need a very powerful fan.

50-100CFM (cubic feet replaced per minute) is fine. In this case, more is hardly ever a bad thing. You want to make sure your fan can handle being attached to a carbon filter without dying in CFM rating, as that’s important for negatively pressuring your tent and avoiding smell.

Part 2 | Part 3 | Part 4

Sources Cited


Author: Budsman


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[…] gives his (not so) expert opinion on how to grow your own dank nugs using a coco coir setup. The first, second and last parts of this series can be found […]

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