The BudTrainer Method™
Basics of Cannabis Home Cultivation
Written by cannabis production expert Henrique Dias - Edited on Sep 30,2024
DISCLAIMER: Everything taught and sold by BudTrainer® is to be used strictly for legal purposes. We condemn the production of illegal substances and it is your duty to ensure that you are complying with the law. The words "hemp", "cannabis", "weed", and "marijuana" are used interchangeably to refer to the same plant (legal hemp with less than 0.3% THC) for the purposes of this lesson.
Master the Basics & Grow Big Buds
Growing high-quality cannabis is nothing more than growing healthy plants. Plants that thrive and love their environment while producing top-shelf bud. And guess what? In order to grow healthy plants all you have to do is learn the basics about cannabis cultivation, and make sure that you don't screw up. In fact, 90% of growing cannabis is simply not screwing up. If you are growing for the first time, this lesson will teach you the basics of growing cannabis.
1. Growing Weed Indoors vs Outdoors
- Cost - which one is more expensive?
- Quality - which one yields better results?
- Schedule - how long do plants take to grow?
These questions are important because they will help you decide whether you are going to be growing indoors or outdoors. Let’s look at the differences between both.
1.1 Cost - Indoors vs Outdoors
Growing marijuana outdoors is a lot cheaper than growing indoors for one main reason: the sun is free and provides a lot of energy to your plants, yielding large amounts of weed at the end of the year. You can easily grow plants that yield ½lb to over 1lb of weed with as little as $100 per plant (pots, soil, nutrients, etc).
If you can grow 1 plant in your backyard with $100 and have a yield of up 1lb, this is the same as paying $0.22 per gram. Not to mention that for most people, 1lb of weed is more than enough for the whole year!
Growing marijuana indoors, on the other hand, costs more before AND after you start growing. A decent indoor setup that grows 1lb of cannabis every 4 months costs around $1,000, the electricity bill will come to around $200 per year, and everything else (nutrients, water, etc) adds another $200.
This means that, in the first year alone you are spending $1,400 for 3lb of weed. If we were to add nutrients and water to the bill, this means you are paying an average of $1.03 per gram in the first year, and as little as $0.30 per gram every year thereafter (compared to $0.22 from outdoors).
1.2 Quality - Indoors vs Outdoors
Growing cannabis outdoors is always dependent on the conditions of the environment around your plants. If it rains too much, your bud won’t be as good. If there are too many bugs or mold, your bud won’t be as good. If it is too dry, your bud won’t be as good. And so on. Basically, the quality (and thus the THC content) of your outdoor plants is directly proportional to the quality of your environment.
Since the environment outside is never consistent, this means that growing outdoors will always see a few bad days here and there, which inherently will compromise the quality and THC content of your bud.
In fact, most licensed commercial outdoor cannabis growers end up selling their cannabis for extraction since they don't pass the microbial tests required at the lab, and nor do they get the high-THC levels that indoors cannabis does.
Growing cannabis indoors, on the other hand, removes all of the problems that the outdoors environment creates. When growing marijuana indoors you can set a consistent temperature and humidity, you can adjust the height of your lights, and your plants are never at the mercy of the weather.
A controlled environment is always better for cannabis, which is why growing indoors yields the best and cleanest results, and as such more potent and higher quality bud.
1.3 Schedule - Indoors vs Outdoors
Growing weed outdoors requires you to stick to the schedule of the sun. In Northern US States and Canada, the earliest you can safely plant marijuana plants outdoors is May, and the latest you should harvest is at the end of October. As a rule of thumb, if it is below 50F/10C outside then it is too cold for your plants.
Growing weed indoors, however, puts the schedule fully under your control and you never depend on the season to grow. You can start and finish your plants whenever you want, and you can also grow during the Winter months. This allows you to get 3 or 4 harvests per year in a single grow tent, under your own terms.
2. Growing Indicas vs Sativas
Before we talk about indicas and sativas, it is important to note that there are almost no 100% pure sativas or indicas in the world today. Most strains today are hybrids, some of which are more sativa-dominant while others more indica-dominant. Your seedbank should be able to inform what kind of strain you are purchasing.
2.1 Leaf Shape & Plant Size
Indicas have much wider leaves, which means they need to be defoliated and pruned more often since their leaves block a lot of airflow and light absorption from below the canopy.
Sativas have thin-fingered leaves with much more space between each leaflet, which means they don't need to be defoliated nearly as much as indicas do.
Indicas grow to be much shorter plants, which is why they are so popular for growing indoors and are the most common form of illicit cannabis available.
Sativas, however, are much taller and lankier, and they need a lot more training in order to keep their branches tame. This is why they are a great choice for growing outdoors.
2.2 Internodal Spacing
Internodal spacing means the space between two nodess, or growth sites, on a cannabis plant.
Since they are shorter, indicas have much shorter internodal spaces. This means they grow pairs of leaves and branches very close to each other.
Sativas, since they are much taller, have long spaces between their branches and leaves.
As a consequence, indicas need to be pruned more often while sativas need to be low-stress trained more often.
2.3 Flower Size & Timing
Indicas have fewer but much denser buds, sometimes as thick as a fist. This means you need a lot of airflow while flowering and while drying, or mold can form in your bud.
Sativas have a lot of smaller buds spread throughout the branches. While this is not a concern for mold, sativas do take a lot longer to trim since their buds are smaller.
Indicas finish their flowering stage after 7 to 9 weeks whereas sativas take 9 to 12 weeks to finish. This means you can grow more indica plants in one year than sativas, since they will almost always be a few weeks ahead in the flowering cycle.
3. Vegetative vs Flowering Stages
Did you know that marijuana has two stages of growth - one for growing only branches and leaves and another for only growing flowers (i.e. bud)? That’s right! Unlike tomatoes, which grow branches, leaves, and fruit at the same time, cannabis plants can only do one thing at once: either grow branches and leaves (called the vegetative stage), or grow flowers AKA bud (called the flowering stage).
What causes weed plants to switch from the vegetative stage to the flowering stage is the availability of light AKA photoperiodism. When cannabis plants get 16h or more of light per day, they stay in the veg stage. However, when they get 12h of light or less, they automatically switch to the flowering stage and start producing buds. Let’s understand why.
3.1 Veg to Flower Natural Switch
When days are long and the nights are short, weed plants think that it’s Spring and Summer time, so they only grow branches and leaves in order to gain as much size as possible.
However, as Fall approaches and the days get shorter, cannabis plants realize Winter is coming to kill them, so they switch to the flowering stage (around August), when they only grow flowers in order to reproduce and make seeds before they die of cold. It’s a smart strategy for them: grow when there is light, reproduce when there isn’t.
The plants below are both in the veg stage, growing only branches and leaves, branches and leaves.
3.2 Veg to Flower Artificial Switch
What photoperiodism means for growing cannabis indoors is that if you leave your lights on for 18h and off for 6h, your plants will think it’s Spring and stay in the veg stage. You can stay in the vegetative stage for as long or as short as you would like, as long as the lights are in the 18h/6h schedule. In the BudTrainer method we recommend staying in the veg stage for 6 to 8 weeks, but if you want to grow massive plants or do a canna bonsai, you can leave your lights on for 18h/day for multiple months.
In order to flip your indoor marijuana plants to flower, simply switch your light schedule from 18h/6h to 12h on and 12h off every day. Your plants will be tricked into thinking it’s Fall time, and will start producing flowers instead of branches and leaves only. The flowering period, different from the veg stage, doesn’t last indefinitely - in 8 to 12 weeks your plants will be ready for harvest (depending on which strain you are growing).
However, there is one exception to photoperiodism: autoflowers.
4. What Are Autoflowers?
Similar to photoperiodic cannabis plants, autoflowers can only either grow leaves and branches, or they can produce flowers - but never both. However, autoflowers don’t care about the light cycle in order to flip to flower - they flip even if under 24h of light per day (i.e. 0 hours of night). While autoflowers don't reach levels of THC as high as photoperiodic strains, they are getting up there quickly and it is just a matter of time until autoflowers are as potent as their cousins.
Most autoflowers have a veg cycle of 20 to 30 days until they automatically switch to the bloom cycle, which lasts 55 to 70 days. This means you can go from seed to harvest with autoflowers in as fast as 75 to 100 days (depending on the strain). While autoflowers still don’t have the same high-THC profiles as photoperiodic plants, they are very close and are a great choice for many growers.
4.1 Growing Autoflowers Outdoors
If you are growing autoflowers outdoors, they won’t care about what time of the year it is in order to flower since they are not sensitive to light.
In fact, if you select a 75 to 90-day strain, you can plant one batch of autoflowers in early May, harvest them in late July, and plant another batch in July for a late October harvest. Many outdoors commercial growers, like in the photo below, do this so that they can get two crops in one year, and so can you.
4.2 Growing Autoflowers Indoors
If you are growing autoflowers indoors, you can keep your lights on for 18h to 24h a day the entire time and your autoflowers will be ready to harvest in 75 to 100 days without your ever having to switch to 12h/12h.
TIP: For maximum yield, leave your lights on for 20h and off for 4h from seed to harvest. We do not recommend leaving your lights on for 24h a day because this impairs root development (roots like to grow at night).
Behind the Leaves: How do Autoflowers Flower?
While some regions of the world have very short days in the Winter and long days in the Summer (e.g. Greenland), other regions have almost the same day-length all year long (e.g.. Thailand).
Since the switch from Summer to Fall is too fast in regions far North and South (i.e. it goes from hot to cold very quickly), cannabis plants that grow in those regions don’t have time to wait for the days to become short in order to start flowering - they must do it while the days are still long, or they will end up frozen in Winter before they could mature their seeds.
Conversely, strains that are too close to the equator can’t rely on day length to flower because every day has 12h of light and 12h of dark, all year long. Because of this, autoflowering cannabis plants had to rely on a system called the C:N ratio in order to flower. Let’s see how it works.
The C:N Ratio
The Carbon to Nitrogen Ratio (C:N Ratio) is a phenomenon that triggers the flowering cycle on plants, just like changing light cycles does. More precisely, this happens after the amount of assimilated carbon (C) in the plant compared to nitrogen (N) surpasses a certain threshold.
When this ratio is high enough, it means your plant has stored enough sugars (Carbon = Carbohydrates) in relation to leaves (Nitrogen) to start the flower cycle and sustain those flowers until it dies.
It’s as if your plants said: my tanks are full of sugars and I can get all the way to the end of the flower stage with this much energy. And so they flower. The autoflower below just started showing it's very first white pistils on the top node.
5. Cannabis Male vs Female Plants
Most plants in the world are monoecious, which means they have both male and female organs on the same plant, which allows them to pollinate themselves. Cannabis, however, is a dioecious plant, meaning it has plants that only produce flowers with male organs and plants that only produce flowers with female organs.
When the pollen from the male flower lands on the pistils (the white hairs that stick out) of the female flower, a seed is born. While male plants don’t have any cannabinoids and can’t get you high, they will pollinate your female flowers and yield lots of seeds. This is why, whenever you identify a male plant in your garden, you should remove it as fast as possible (unless your intention is to breed).
How to Identify Cannabis Sex
Most plants in the world are monoecious, which means they have both male and female organs on the same plant, which allows them to pollinate themselves. Cannabis, however, is a dioecious plant, meaning it has plants that only produce flowers with male organs and plants that only produce flowers with female organs.
When the pollen from the male flower lands on the pistils (the white hairs that stick out) of the female flower, a seed is born. While male plants don’t have any cannabinoids and can’t get you high, they will pollinate your female flowers and yield lots of seeds. This is why, whenever you identify a male plant in your garden, you should remove it as fast as possible (unless your intention is to breed).
6. Feminized Marijuana Seeds
Most cannabis seeds are non-feminized, meaning you have no idea whether what you are planting is a male or a female plant. You always have to wait until your plants flower in order to tell which is which.
Feminized seeds, on the other hand, are seeds that always yield female plants. Instead of risking your plant being born a male, feminized seeds remove that risk altogether. While they are more expensive than regular seeds, feminized seeds are worth every penny because there is nothing worse than growing a male plant for weeks, finding out it is a male after it has flowered, and then having to throw it out in the garbage.
Behind the Leaves: How Feminized Seeds are Made
In order to tell if a cannabis seed is a male or a female, you would need to run a DNA test, and in order to do that you would have to crush your seed in order to get to the middle of it, which would automatically destroy it. This means you can't tell whether a seed is male or female, even with existing technology.
Before we understand how feminized seeds are made, we need to understand what cannabis hermaphrodites are.
Cannabis hermaphrodites
Hermaphroditic weed plants are plants that have both male and female flowers. Hermaphroditism happens genetically to a very small percentage of cannabis plants that were just born that way, but it happens most often when cannabis plants get really stressed, such as being too close to the lights, high temperatures, lack of fertilizers, or dry media.
When stresses like these happen, the female flowers think they are under existential threats and as a result they put out a few male flowers (also known as bananas or nanners) in an attempt to auto-pollinate, and at least generate a few seeds before it dies. The photo below shows a clear example of these male pollen sacks (in yellow).
Female DNA
The thing is, the male flowers that are created in a female plant due to stress have 100% female DNA since they were born out of a female plant. When these male flowers pollinate the female flowers from the same plant, they end up producing seeds that also contain 100% female DNA (50% from the male and 50% from the female) - which is why seeds born this way always end up growing female plants - AKA feminized seeds.
In order to commercially make feminized seeds, breeders choose their best female plants and then spray them with silver nitrate or silver thiosulfate, which are both inducers of male flowers in female plants. This plant under the purple light was sprayed 3 weeks before the picture was taken, and now it has both pollen sacks and pistils in the same female plant. This plant is ready to auto pollinate and generate feminized seeds.
You Are Off To A Great Start
Now that you know the basics of cannabis growing, it’s time to get your seeds picked and planted!If you are ready to learn the best way to plant (and transplant) cannabis seeds, check out Lesson #1: How to Plant Cannabis Seeds.
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About The Author
Henrique, the CEO of BudTrainer, is a mechanical engineer with a commercial cannabis production post-grad, and is also a former commercial cannabis consultant.
H takes plant science principles and breaks them down into simple steps for home growers to achieve the same results as the pros and grow the highest-quality cannabis.
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