How to Train Cannabis Plants for Maximum Yield

Updated on April 12, 2022

Cannabis flowers and colas inside a reflective indoor tent.

" First off, why do people train their cannabis plants?"


" Simple! It all comes down to a few key elements..."  


1. It Increases Yield

2. More Cannabinoids

3. Less Grow Space

4. It Decreases Pests


Did you know that...



Over 95% of legal commercial growers train their plants? Not only do they spend money buying training equipment, they also spend a lot of paid labour making sure their plants are well trained. This is a large investment, meaning they must be  making that money back.


If 95% of legal commercial growers train their plants, why shouldn’t you?

No more waiting. Let’s get right into it!




"The BudTrainer"

Method







Tools needed:


*If you don't have LST pots, just poke holes on the rim of your pots


Difficulty level: 

Beginner

Timeline: 

6 weeks (seed to flower)

Space needed: 

2' by 2' per plant

Need training supplies? Go ahead and grab yours now!



Maximize your yields in just 7 steps...




1st Step: pruning the 1st node

When: after 6th node appears



What to do: cut off the 1st set of true leaves + shoots (the little branches that come out with each leaf) on both sides of the 1st node (node = pair of leaves + shoots opposite to each other). This is important because the shoots on the 1st node tend to grow into smaller branches than the upper nodes. 

Don’t confuse the first node with the cotyledons. Cotyledons are the very first small round leaves that come out of your seed and feed your plant with nutrients until it has roots. You can either remove or leave the cotyledons - it doesn't matter.

cannabis seedling planted inside the BudPots in a diagram showing the first shoot and first true leaf

Cannabis seedling with 2 grown nodes, and a 3rd node coming out


2nd Step: topping for the 1st time

When: at the same time as Step 1



What to do: top your plant (cut the top off) above the 5th node, leaving all shoots and all leaves from nodes #2, #3, #4, and #5 (there should be a total of 4 nodes/8 shoots left).

These 8 shoots will grow into your plant’s main branches in the future. If you would like to understand how to top your plants in more detail, read this article

Topping above the 5th node and leaving 4 nodes/8 shoots behind


3rd Step: low-stress training

When: after shoots grow 4" to 6"



What to do: low-stress train (bend) all 8 branches to grow sideways at an even angle from each other (like a pizza with 8 slices), using your LST clips on the top branches, your perforated pots and garden ties on the lower branches.

You may also defoliate the old leaves that are being blocked by the upper branches or that are blocking the branches below them from getting light.

Training the 8 grown branches, and lightly defoliating

Cannabis plant trained with 8 BudClips into a manifold shape

Low-stress training only with the BudClips

Cannabis plant trained with 2 BudClips and 6 BudHuggers inside of the BudPots into a manifold shape

Low-stress training with the BudClips, BudPots, and BudHuggers


4th Step: topping for the 2nd time

When: new branches on 3rd node



What to do: wait another week to allow the branches to put on some thickness and length, then top each branch that has 3 nodes or more (cut after the 3rd node). Each branch that was topped should now have 6 new branches each, but we recommend removing all branches that facing down or that are smaller than their respective pair.  

Also, take this opportunity to re-tighten your BudHuggers on the BudPots, and re-apply your BudClips higher up on the plant. This will ensure an even wider canopy before flowering.

NOTE: do not top the branches that have less than 3 nodes - instead, remove the lower shoots from those branches in order to encourage the top ones to grow stronger. See video.

Topping for the 2nd time, lightly defoliating, & re-training branches

Cannabis branch with two leaves and two shoots, where one shoot is smaller than the other and has an arrow pointing to it

When two shoots are asymmetrical, prune the smaller one


5th Step: flipping to flower

When: 1 week after last topping



What to do: wait one week from the last time you topped your plant, and flip it to flower. This is the same plant from the video before, 7 days later and ready to flower. 

The reason why it is not recommended to flip your plant to flower before 1 week is because it is still recovering from topping, and it won't grow as vigorously as it can. It is also not recommended waiting too much longer, or many small branches will form and yield popcorn bud. 

Cannabis plant trained into a manifold shape with 8 branches split exactly at 45 degrees from eachother

This purple khush CBD is ready to flower


6th Step: mid-flower defoliation

When: after week 3 of flower



What to do: defoliate all leaves that aren't catching light or that are blocking the lower buds from the light. We also recommend removing all small branches in the middle of the canopy in order to promote stronger growth at the top buds.

Feel free to tighten up your BudHuggers on the BudPots, but we don't recommend using the BudClips after this stage.

Fact: during the first 3 weeks of flower, which is called the stretch phase, your plant will double its length. During these 3 weeks, we don’t recommend high-stress training, defoliating, or pruning, as these techniques can slow down the stretch.

Defoliating after the third week of flower (stretch phase)


7th Step: late-flower defoliation

When: 1 week before harvest



What to do: defoliate all fan leaves that are still on the plant. This will allow some light to penetrate deep inside your canopy, which will help the lower buds fully develop. Here is what your buds should look like after defoliation.

Fact: this will help tremendously when you actually need to harvest and trim all of that bud, since you will have already done most of the work. It also promotes stresses within the plant which help increase cannabinoid production.

Cannabis flowers with purple leaves after defoliation

Flowering plants that were defoliated 1 week before harvest


And you are done!



After the last defoliation is complete, wait about 1 week and you are good to harvest!



But wait... what about the science?


Or skip to...

" How does plant training really improve cannabis yields? "


"The truth might surprise you... plant training doesn’t actually increase yields..."


What plant training does is that it increases the rate of photosynthesis in your plants, which is a process that combines CO2 from the air and water from the ground with energy from the sun, and transforms them into oxygen and sugars. 


The oxygen from this process goes back into the air (for us to breathe - thanks plants!), but the sugars stay in the plant and work together with other nutrients in order to grow roots, stems, leaves, and flowers (AKA bud!). 

Diagram showing the photosynthesis process on a cannabis plant

Photosynthesis process

Pro Tip: the more photosynthesis, the more bud!




And for more photosynthesis, you need The 3 Pillars of Plant Training...




Ready to train your plants with the most durable products in the market?


The 3 pillars of cannabis plant training



Here are the 3 most effective ways to increase your yields with plant training.



1. Light Exposure

2. Air Exchange

3. Hormonal Distribution


Let's look at how each of these elements contribute to photosynthesis, and how to set up your plants for optimal growth. 


1. Light Exposure




Imagine two plants: one is tall and skinny, and the other is short and wide. When you look at both from the top, which one will have more “leaf space” to collect light? 

Diagram showing the difference in canopy size from a trained vs an untrained weed plant

Tall & skinny vs short & wide plant


As we can see from the diagram above, the trained plant has a much larger surface area when looked at from the top, meaning it is collecting nearly twice as much light as the untrained plant. A good comparison is that training a cannabis plant for light exposure is the same as spreading out solar panels (i.e. your plant's leaves) that were previously stacked on top of each other, so that the bottom panels can catch some light. Here are the two most common ways to accomplish more light exposure.




  Low-Stress Training & High-Stress Training


Hand drawing of a branch being trained with a string and another being supercropped

Low-Stress Training, or LST (on the left) vs High-Stress Training, or HST (on the right)



The first way to gain more light exposure is called low-stress training (LST) and it involves gently bending the branches of your cannabis plant sideways and then tying them with a garden tie. 


The second way to increase light exposure is called high-stress training (HST), which involves bending the branches of your cannabis plants until they "crack" into position, thus removing the need to tie them down. 


While both techniques achieve the same result for light exposure, we don’t recommend HST since it stresses the plant by up to 3 days, while LST only stresses the plant by just a few hours. In fact, HST is used more often as a remedy for when plants are growing too close to the lights and you can't tie them down anymore, while LST is used much more broadly.


If you want to find out more about Low-Stress Training, read this complete LST guide.


2. Air Exchange


Did you know that 99% of the water your plants absorb via their roots evaporates back into the air via tiny little holes under their leaves called stomata? Seriously, your plants are like humidifiers, and the reason for this is that the more they transpire, the more nutrients make their way up with that water and stay inside of the plant. Water works mostly as a nutrient carrier for your plants, as 99% evaporates in the air.

Diagram showing how precipitation gets absorbed into the roots of cannabis plants and then transpire through their leaves back into the atmosphere

Transpiration process


But something else happens while plants transpire and water evaporates. Since the stomata are open, the leaves take this opportunity to absorb CO2 and expunge oxygen at the same time, thus enabling the photosynthesis process. In a nutshell, the more your plants transpire, the more nutrients they take up via the roots, the more CO2 comes in via the leaves, and the more they photosynthesize (and grow).


So, if you want to maximize your transpiration and CO2 intake you need to increase the airflow around your leaves so that they can exchange the outgoing air with oxygen + high humidity with incoming air with CO2 + low humidity. 


To accomplish this, you can do one of two things: you can always use low-stress training in order to “spread-out” the branches and create more air space inside the canopy, or you can also defoliate and prune the old leaves and growth sites that are blocking airflow to the middle of the plant. 

Diagram showing a leaf with a stomata open and allowing co2 in while letting oxygen out

Stomata functionality



In fact, when leaves become clustered they inhibit airflow and also attract many pests. This is why it is important to remove leaves and branches from your cannabis plant in a way that contributes to more air movement. But be careful! Defoliation and pruning can be damaging too. Read this article to learn how to prune & defoliate cannabis plants for maximum yield



3. Hormonal Distribution



The reason why a lot of plants grow toward the sun in a Christmas-tree shape is because they produce high levels of growth hormones (called auxins) nearest the top of the plant, while inhibiting the side branches from getting it. This phenomena is called apical dominance, and is the reason why cannabis grows one tall cola in the center and many smaller ones off to the side. This plant, for example, grew “naturally”. You can see how much thicker the top cola is compared to the side ones. This is not good because it means you get some good bud from the very top but a lot of popcorn bud from everywhere else.



two different cannabis plants: the one on the left has not been trained at all while the one on the right has been low stress trained

Untrained plant (on the left) vs Trained plant (on the right). The colas are much thicker on the trained plant.



How the hormones work



Generally, indoor growers want their plants to grow as much cannabis as possible, but they also want to use as little space as possible. Training marijuana plants allows you to control their final shape, meaning that you can make them as short or as wide as you want in order to fit whatever space you have to work with. 


There are two main ways to better distribute auxins throughout the plant. We can apply LST or HST to bend the top of the main stem horizontally, such that the side branches become level and start growing stronger. The second way is called topping (ta-da!), and over 90% of legal commercial growers do it in order to improve their yields. Topping involves cutting the growing tip of a cannabis plant so that all the auxins that were being produced there can now start being produced on the side branches instead. 

Diagram showing how auxins work on a terminal bud: where the sunlight is present, auxins elongate the opposite side.

The effect of auxins on plants



Another way to shift hormones in the cannabis plant is by pruning weak shoots (AKA growth sites AKA new branches) so that they don’t develop into weak colas during the flowering stage. When you remove the weak branches, you give the larger branches an opportunity to grow even stronger (as we learned on Step 4 of our cannabis training method).


Putting it all together




The truth is that there isn’t a single technique or method that works best. What does work best is putting all of these 3 elements - light exposure, air exchange, and hormonal distribution - together in a way that maximizes the rate of photosynthesis of your plants. For this, we recommend doing a little bit of everything depending on your growing space.


Is that all there is to plant training?


" Are there any other benefits to training cannabis plants?"


" Yes! Here are other reasons why you should train your cannabis plants. "


Pest Control




We just saw that airflow is really important for transpiration and CO2 exchange, but we didn’t talk about airflow as a tool for pest prevention. Powdery mildew, which is a very common mold in cannabis, thrives in environments with humid and damp air. This is why you will usually find powdery mildew on the inner leaves of your plant before the outer ones - because they are more humid and have less airflow. Because of this, it is crucial to clear out the inner leaves of your plant (they are usually small, anyways).

Cannabis leaf being held by two fingers, with powdery mildew mould on top

Cannabis leaf with powdery mildew



Spider mites, on the other hand, are tiny bugs that eat cannabis leaves and make webs all over the plant, also like the same type of humid environment and will thrive if the temperatures are high as well. So if you can add some air movement by defoliating your canopy and using training techniques to “open up” your plant, you will make it very uncomfortable for pests to set in, which means they will end up choosing your neighbour's plants instead.

Cannabis leaf with two-spotted spider mites
Cannabis leaf with two-spotted spider mites on the underside

Space Savings




Home growers want their plants to grow as much cannabis as possible, but they also want to use as little space as possible. Training marijuana plants allows you to control their final shape, meaning that you can make them as short or as wide as you want in order to fit whatever space you have to work with. 


With proper training you also don't waste your precious light on the floor of your tent or closet - instead you force your plants to occupy the entire grow space and collect all of the light available to them. In fact, a trained weed plant will almost always give you more grams per watt of electricity because you maximize your leaf area.

8 trained cannabis plants in the flower stage inside a mylar cannabis tent

8 trained cannabis plants inside a 4" by 4" tent


More Trichomes



When you prune the weak branches off of your cannabis plants and train the stronger branches to grow into a wider canopy, you are basically allowing your cannabis plant to focus all of its energies on the remaining, stronger growth sites. This allows these sites to grow even bigger, promoting much higher trichome concentrations at the tops. 


When you don't train your plant, the energy it produces is distributed equally to every branch, weak or strong, and you end up with some bud that is good and some that is bad. It is much better to take control and only grow the good ones.

Cannabis flower full of trichomes and some foxtails

Cannabis flower from a trained cannabis plant

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Time to get some things cleared up...



Frequently Asked Question #1



What is the difference between indoor and outdoor training?




Below are the 3 key differences between training cannabis plants indoors vs outdoors.

1. Light Source



Our sun is almost 100 million miles away from earth, so even if you have an outdoor plant that is 20ft tall, the bottom leaves and the top leaves will feel no difference in light intensity (as long as they are not shaded). However, when it comes to indoor lights the intensity of the light decreases drastically as you get farther away from the source - getting up to 5 times weaker every foot of distance.

What this means is that training cannabis indoors is essential for optimizing light distribution, like for example keeping a flat canopy and defoliating the bottom of the plant (like the plant on the right of this diagram). When growing outdoors, however, you don’t need to worry so much about this - just make sure to choose a spot in your backyard that has the most amount of sunlight, all day long. Cannabis does not like the shade!

Diagram showing two cannabis plants, one untrained and one trained, showing the low intensity zone and the sweet zone for growing

High-intensity vs low-intensity zones for indoor lighting


2. Airflow



As we have seen before, airflow is essential for plants to absorb CO2. For this reason, it is equally important to train indoor and outdoor plants to maximize airflow around the leaves.


The main difference, however, is that outdoors plants have the extra pressure from pests while indoor plants generally don’t. This is why we highly recommend defoliating outdoor plants at least once a month to clear out all old leaves that are turning yellow, not catching any more light, or that are blocking airflow to the middle of the plant. As long as you don’t create pockets of clustered leaves, you should be safe from pests.

diagram showing a defoliated plant and a non defoliated plants

Defoliating outdoors to prevent pests


3. Support



When growing cannabis indoors, we never have to worry about strong winds breaking our stems. But outdoor growing is a different story. We personally have friends who lost entire plants because of strong winds that broke them at the stem. This is not an uncommon story.


Many growers fail to train their outdoors plants and instead let them grow naturally into the Christmas tree shape. The problem with this is that, after flowering, the untrained plant gets very heavy at the top, and any strong wind can break its main stem in half. 


This is why it is crucial to give your outdoor plants the side support they need in order to survive strong winds. You can do this with tomato wires, garden stakes, garden ties, trellis nets, and ropes.

4 outdoors cannabis plants trained with a trellis net and garden stake

Outdoors cannabis plants with garden stakes and trellis nets


Frequently Asked Question #2



What is the difference between training indicas and sativas?



Below are the 5 key differences between training indica cannabis plants vs sativa cannabis plants.

cannabis indica vs cannabis sativa weed plants diagram showing the difference in height, foliage, and leaf

Indicas vs sativas: the different shapes

Indicas



- Easier to train

- Requires more defoliation and pruning

- Only needs to be topped once

- Needs to be trained less frequently

- Lower profile plants


Due to their genetic makeup, cannabis indicas have a sturdy growth structure, with thick fingered fan leaves and short spaces between each set of leaves (called internodal spacing). These features make indicas great for beginners who want to practice all training techniques, including topping, low-stress training, pruning, & defoliation. Since indicas are short and stocky, they are super easy to train when compared to their tall and lanky sisters: the sativas.



Sativas



- More difficult to train

- Requires less defoliation and pruning

- Needs to be topped multiple times

- Needs to be trained more frequently

- Higher profile plants


Sativa cannabis strains have a tall and skinny structure, with longer internodal spacing (space between each node). This makes it extra important to constantly low-stress train and top them so that they stay low to the ground. We recommend topping sativas once every 2 weeks until it is time to switch them to flower. This will ensure your plants don't grow too tall too quickly and end up reaching your lights (indoors) or becoming prone to breaking under strong winds (outdoors).


Frequently Asked Question #3



What is the best way to train autoflowers?



Training auto-flowers is definitely not the same as photoperiodic plants. Here is why.

Two autoflowering marijuana plants with a BudTrainer sticker at the back, in between the two

Two autoflowers that were low-stress trained and will be ready to harvest in 1 week



Autoflowers only have around 30 days in the veg stage before they automatically go into the flowering stage (AKA “auto-flower”), so it is best to only use low-stress training techniques on your auto-flowering plants and never top them! Here is a complete guide on how to low-stress train cannabis plants for maximum yield


You should also avoid high-stress training or pruning, as they will also cause too much stress on your autoflowers and stunt their growth for a few days. Since autoflowers have such a short cycle, a few days is too much to afford and you will lose a lot of potential growth (and bud). In a nutshell: only LST your autoflowers, never top them, and only remove old and yellow leaves or very small shoots in the middle of the canopy.


Don't be afraid!



It is very common for new growers to fear training their cannabis plants. After all, you are hurting them by doing things that seem very counterintuitive. The thing is, if you get unlucky and break a branch that you can't tape back together, your plant will automatically start growing out the other branches and you won't lose much yield. All in all, it’s better to try and screw it up a few times while learning, because plant-training will be with you forever!



Happy growing, friend!






Want to continue learning? Here are a few more lessons for you!


Lesson #1: Cannabis Growing Basics And How to Select Seeds for Maximum Yield
Learn the basics of cannabis growing and get ready to select the best seeds for your growing environment after reading this complete guide. Here at BudTrainer, our mission is to help cannabis lovers grow top-shelf weed at home, like the pros do.
How to Harvest, Trim, Dry, and Cure Cannabis Plants for Maximum THC Potency
Want to learn the best time to harvest your weed plants? Should you dry trim or wet trim marijuana? What relative humidity should you dry your cannabis plants at? How long does curing really take? All of these answers, and more, in this unique harvesting, trimming, drying, and curing guide by BudTrainer!
Lesson #2: How To Plant (and Transplant) Cannabis Seeds for Maximum Success
Have you ever wondered why people plant and transplant their cannabis seeds, instead of just sowing directly into the ground? It comes down to growing more roots, and more shoots. Come on in and learn how to plant and transplant cannabis plants like a pro!
How to Mainline Cannabis Plants Like a Pro
Are you looking to hone your cannabis training skills by trying the infamous mainline? If you want to learn where the mainline came from, and how to apply this technique to your plants, this is the most complete guide available online!
How to Defoliate & Prune Cannabis Plants
Have you ever wondered how much (or how little) to defoliate your cannabis plants? Do you know what are the best times to defoliate? Plus, what's the science that proves defoliation is actually effective? Find out all of these answers in this article!
How to Top Cannabis Plants: The Method & The Science Behind This Old Trick
Do you want to get bushier plants and bigger yields? Wait no longer and check out this complete guide on how to top your cannabis plants and increase your yields as well as the quality of your buds. We cover both the science and the method behind this old growers trick, so come on in and have a read!