Cannabis growers often want cannabis plants to grow into a certain size and shape to produce the best yields.
As a grower, you can control a lot of the final size and shape of your plant by using proper cannabis training and growing techniques, such as topping, FIMing, LST, main-lining, supercropping, defoliation, SoG, ScrOG and more. However, no matter how well you train your plants, some grow patterns are going to be determined by your plant's genes, especially in the flowering stage. You can control the genetics by choosing to start with a great strain, and this page will explain everything else you can do to get your cannabis to grow the way you want, so you get the best yields possible.
Many indoor and outdoor cannabis growers prefer to keep their plants relatively short, growing bushy and wide instead of tall and thin. This helps make sure the plant gets plenty of light - light is like "food" for your plants, and providing the right amount of light will give cannabis plants the energy to grow.
Light is Like "Food" for Cannabis Plants
For outdoor growers, plant training helps with better stealth and yields. The sun is all the light an outdoor cannabis plant needs to survive (as long as it's getting direct light for the majority of the day). But most outdoor growers are looking to make their cannabis grow in a way that produces the most amount of bud for the size of the plant, while keeping plants low profile so they're harder to spot from far away.
Outdoors, a bushy cannabis plant produces the best yields for the height because more of the plant is getting light from the sun at any one time. Outdoor growers also often need to be able to prevent their plants from growing too tall. This is accomplished at least partly with cannabis training methods.
Why do indoor cannabis growers want short plants?
For indoor growers, plants tend to yield more if a lot of the plant is kept just the right distance from the grow lights. This means trying to maintain a flat cannabis canopy under the grow lights and almost always using growth training methods like topping, FIMing, main-lining, ScrOG, etc. These training methods help make sure all the buds get as much light as possible, so you get bigger yields from the same grow lights.
Why do cannabis plants need to be close to the grow lights? It is because indoor grow lights follow the inverse square law of light. The light from indoor grow lights is not like the sun. The sun is so far away that the inverse square law of light doesn't make a difference - your plant will get about the same amount of light whether it's on the ground or 10 feet in the air.
Using indoor grow lights is different from growing under the sun. The further away a plant is from an indoor grow light, the less light the plant will receive. With grow lights, the amount of light received by the plants drops off fast as plants get further away.
This is a huge part of why it's important to understand how far away your lights need to be, depending on what type of light you have.
Learn more about cannabis grow lights
Powerful Grow Lights - Some grow lights are very bright and powerful (like MH/HPS grow lights or high-powered LEDs). The more powerful a grow light is, the further it will generally need to be kept from your plants, but in many cases more powerful grow lights will also be able to cover a greater area. Whenever buying MH/HPS grow lights or LEDs, it's important to understand exactly how far away to keep the lights from your plants. With MH/HPS lights, this is easy to know. For LED grow lights, it's important you ask the manufacturer how far away the LEDs should be from your plants. You need to know the "sweet spot" where your cannabis plants are getting just the right amount of light, so you can train your plants to take advantage of it.
Less Powerful Grow Lights - Grow lights like CFLs and fluorescent lights have a "sweet spot" that is only a few inches away. The further you get, the less light your plants get. These types of lights can grow cannabis plants, and may be a good choice for some growers, but with less powerful lights, it becomes even more important that you learn how to train your plants to grow short and wide with many colas. Luckily the methods on this page like topping, FIMing, SoG, ScrOG, main-lining and more will give you the tools you need to get the most from your grow lights. By using plant training techniques, it becomes possible to harvest ounces of bud even from relatively small grow lights.
What distance should your grow lights be from your plants?
Learn what you need to know about grow lights here: http://www.growweedeasy.com/grow-lights
Leaves in the "Sweet Spot" of Your Indoor Grow Light Make the Most Energy, Producing Faster Growth and Bigger Buds
In the above diagram, you can see that the natural plant (left - completely untrained) has less parts of the plant in the best light. As a result, this plant only has one big cola, and the rest of the colas are much smaller.
Why settle with just one big cola when you could have many huge colas?
The trained plant (right - which has been topped and trained with LST) has many colas that are directly in the sweet spot. In fact, almost the whole plant is getting bathed in just the right amount of light from the grow lights. This means the plant has many big colas.
A plant with many colas in the sweet spot will end up yielding more than a plant with just one main cola. So make sure you know what the sweet spot is for your indoor grow lights!
Generally, the top of the grow light sweet spot is where the biggest buds form. Cannabis plants love a lot of light, much more than your average house plant. As long as you stay away from the "too bright" zone for your particular indoor grow lights (which can cause light burn, even if air is cool), you want to get as many colas in the top of the sweet spot as possible.
Colas in the Top of the Sweet Spot Grow Biggest
It doesn't matter what type of grow light you use. Each type of grow light has a sweet spot, and indoor growers can maximize their yields by training the plant so that the majority of the plant and colas are taking advantage of the best light.
Cannabis uses light to grow and make buds. Indoor growers want to make sure that the majority of the plant is bathed in just the right amount of light. This is accomplished with cannabis training techniques like topping, FIMing, LST, supercropping, ScrOG, SoG, main-lining, defoliation and more (all explained below).
Maximize Yields by Training Cannabis Plants For Many Colas Bathing in the Exact Right Amount of Light
Different grow lights need to be kept at different heights from cannabis plants, but in almost all indoor growing setups, there are benefits to training your cannabis plants to grow short and wide. By having more of your plant at the best distance from your grow light, your cannabis leaves will be exposed to more light and give your plant more energy to grow.
When your grow lights are positioned above your cannabis plants....
Plants with a flat canopy will produce more energy than tall & thin plants
There are a couple of different techniques that you can use to get cannabis to grow more wide & bushy as opposed to growing tall. This will give you the ability to grow lots of fat colas instead of just one.
This page lists some of the most common cannabis training techniques, including information about plant training techniques such as LST, supercropping, main-lining, ScrOG nets, SoG and cutting/pinching techniques like topping and FIMing.
As an indoor cannabis grower, you don't have to just accept the way cannabis grows naturally. You actually have a lot of control over how your cannabis plants grow. So train your plants to efficiently fill up your grow space, giving you the best yields possible with your grow lights.
Learn more about cannabis grow lights:
When growing cannabis indoors or outdoors, it is your responsibility as a cannabis caretaker to ensure that your plants grow the way you want. The following techniques will give you the power to grow a cannabis plant that fits in whatever space you desire.
Get Set Up For Effective Cannabis Plant Training
Choose the Right Cannabis Strain
The strain of cannabis you start with has a huge effect on how your plants will grow, especially while making buds.
A cannabis plant's style of growing is greatly affected by its genetics. The plant tends to grow like its parents.
While different strains show different characteristics, most cannabis plants grow somewhat similarly in the vegetative stage (first stage of life). Strain does have an effect on vegetative growth, but things get really different when the plants switches from vegetative to flowering.
Oftentimes the tendencies displayed in the vegetative stage become a lot more exaggerated in the flowering stage. If a plant is growing tall and fast in the vegetative stage, that will likely happen even moreso in
When cannabis reaches the flowering (budding) stage, different strains tend to start growing more differently from each other. Some strains grow very tall after being switched to flowering, doubling or tripling their height (or more). Other strains stay short and squat after being switched to flowering, and may not stretch much at all.
A strain that is labeled...
As you enter flowering, the genetics begin to really show.
Let Me Show You: These plants were grown together. The one of the right starts out a bit taller, and grows just a little lankier than the other one. But generally they've stayed about the same height for the vegetative stage. Now look what happens when they get switched over to the flowering stage...
Mismatched Cannabis Strains Are Not Effective
Prepare for the Flowering Stretch!
Choose Strains to Match Your Setup and Each Other
What Does Strain Affect?
Many of these factors can be affected by how you grow your plants, but you're much more likely to get exactly what you want when you start with the right strain.
Where can I get the strain I want?
What about bagseed? Many growers do not have the option to choose a specific strain. First-time growers often use bagseed (seeds they find in their cannabis), and may not know anything about the plant they're growing. When this happens, it can be hard to predict how the plant will grow in the flowering stage, but you can use the techniques on this page to encourage your plant to grow the way you want.
Which strain to start with?
One of the more popularly recommended strains for new growers is...
I grew Northern Lights for my first grow, and I was very happy with my results. However, I've seen first-time growers succeed with many different strains. Of course it's important to look at the characteristics of the strain and pick one that will be suited to your grow space, but in my opinion the most important thing is to choose a strain you want.
Most Importantly, Choose a Strain That Excites You!
Whether you want to grow a famous strain, try something new, or pick a strain for your medical marijuana needs, you'll be able to find what you're looking for when buying cannabis seeds online.
There are two main types of cannabis, photoperiod (most plants) and auto-flowering.
Photoperiod (Nearly All Strains)
Nearly all cannabis strains are photoperiod and need 12-12 lighting to make buds. If you don't know what type of seed you're starting with, it is almost always a photoperiod strain.
Unless a grower specifically says their plant is an "auto-flowering" plant, you can assume they're talking about a photoperiod cannabis strain.
Strains that are auto-flowering automatically start making buds after a few weeks, regardless of light schedule.
Auto-flowering strains are popular for indoor growers who cannot light-proof their grow area, or do not want to worry about light schedules. Autos can also be useful for outdoor growers who are normally dependent on the seasons to determine harvest time.
Make sure you always buy seeds from a reputable breeder!
Indoors: Get the Right Grow Light For Your Space
If your marijuana plant has no problems or illnesses, then the biggest factor that affects your yields is the light intensity received.
More Light = Bigger Yields
Of course this isn't true in all cases, but cannabis plants need a lot of light.
Can You Provide Too Much Light?
Yes, there is a point when you can provide too much light to your plants (causing light burn, bleaching and other problems), but most indoor growers won't hit that point unless they keep lights too close to the plants.
Outdoor growers just need to make sure they don't increase the amount of light too fast (don't move an indoor plant into direct sunlight without giving the plant some time to adjust). But once a cannabis plant is used to being outdoors, it's difficult to give them too much light from the sun. Cannabis likes 8+ hours of direct sunlight every day for best growth.
After choosing your strain, one of the first things you want to do is ensure that the plant is getting the right amount of light. It's common for new indoor growers, especially those on a budget, to not provide enough light for their cannabis plants.
What Happens When Cannabis Doesn't Get Enough Light?
During the vegetative stage, cannabis plants which don't get enough light will tend to 'stretch' up toward the light with a lot of space between nodes or "branches." This is not usually a good thing, because tall lanky plants are hard to give proper light coverage in flowering, and may not be able to hold themselves up without support.
Not enough light in the vegetative stage
Once cannabis plants are in the flowering stage, light intensity is what drives the production of buds. Cannabis plants can use more light in the flowering stage than in veg. Not providing enough light will result in smaller, airy buds and lower yields.
For best results, you want all your buds directly exposed to strong light. This seems to cause buds to swell up much more than when the buds are hidden from the light. In the wild, cannabis plants are pollinated by the wind, so it makes sense that the buds that are exposed to wind and light tend to get bigger (buds hidden in the inside of the plant are unlikely.
Not getting enough light in the flowering stage
The rest of this article is going to cover all the different ways to get your plants to grow in a way that makes it easy to expose all the buds evenly to intense light.
Get the Right Sized Container or Pot for Your Cannabis
When your cannabis roots don't have room to expand, it will tend to keep your plants from growing as big as they could.
Hydroponic growers can often get away with smaller containers for their roots than soil growers. This is because they provide nutrients directly to the plant roots in their water - plant roots don't need to seek out nutrients like they do in containers.
Learn more about Soil vs Hydro:
A cannabis plant who's roots have grown too big for its container is known as being "root-bound" because the roots are bound up together in too small a space.
Smaller pots tend to keep plants smaller, but too-small containers can trigger problems because roots don't have enough space to thrive.
Cannabis roots that are kept in too-small containers a long time are much more prone to nutrient deficiencies and other problems, especially when kept in very small containers. The roots just don't have room to expand and do their job properly. Roots will be fine at first, but as time goes on, it will become harder and harder to keep a root-bound plant healthy.
Choose a Container (general guide)
Your final desired plant size is...
12" tall plant - 2 gallon container
24" tall plant - 4 gallon container
36" tall plant - 6 gallon container
48" tall plant - 8 gallon container
60" tall plant - 10 gallon container
What size container should I use for my potted plants?
Cannabis plants can survive in too-small containers for a time, and will be healthy - at first. The problems start once the cannabis plant becomes root-bound, which happens after your plant has been kept in a small container for too long.
If plants become root-bound, you will need to transplant your plants into a larger container to prevent any further problems.
Some growers choose to use the power of smaller containers to encourage smaller growth.
When your cannabis is kept in a smaller container, you will notice that you have to water your plant much more often than if you kept your plant in a big pot.
How often should I water my cannabis plants?
Plants are also more likely to suffer from nutrient deficiencies and root problems because the roots aren't being give enough room to spread out.
Keeping plants in tiny containers is sometimes important when growing in a very space-limited grow space, such as growing in a space bucket for stealth reasons. But I never recommend growing cannabis in a container that is smaller than 2-gallons, such as the ones pictured here.
There are many powerful growth control techniques explained below that allow you to grow big high-producing plants while keeping them short, and there is no need to grow in a too-small container.
Plant Training Techniques
Low Stress Training (LST): Control Cannabis Grow Patterns with Bending
LST is a commonly used term in the cannabis growing community. It simply stands for "Low Stress Training."
LST technique is considered a "gentle" way of controlling how cannabis plants grow. Unlike the more aggressive methods listed below, low stress training such as bending, tying down, and supercropping do not involve cutting your plant.
The idea of LST is to actually 'bend' and otherwise gently manipulate the plant to get plants to grows in the shape you want while creating new colas for buds to grow on.
For most indoor cannabis growers, the goal is for flat, horizontal rows of buds, instead of the natural "Christmas Tree" shape.
LST is a gentle and effective training technique for all cannabis plants
While LST is useful for all growers, LST is pretty much the only training technique that can be used for auto-flowering plants.
Low stress training involves bending tall branches and using gardening wire or soft ties to hold down the branches.
Here's a great LST example by Santacabrera showing how to gently bend the middle colas of a plant down and away from the center without cutting or harming the plant.
Bend too-tall branches down and away from the center of your plant
When growers LST their plants, the general idea is to gently pull branches away from the middle of the plant, so that the plant looks like a star when viewed from above. This helps expose the lower branches to more light, while also keeping plants short.
These growth nodes will become new colas once they're exposed to light and air
This technique can be used on plants that are getting too tall for your setup, or are growing taller than your other plants. Most growers want to keep an even canopy when growing indoors to get the most from their grow lights.
If you plan on using LST, I highly recommend getting a spool of twisty tie or coated wire to tie your plants down with. There are many options available at your local gardening store or online, or you can rig something together yourself.
Don't use string or anything sharp to hold down your plants for LST!
Anything sharp can cut into your plants as they grow bigger, which you don't want. Open wounds are not good for cannabis growth. But soft wire ties, twisty ties, or anything soft and bendable will work perfectly without hurting your plants.
Twisty ties are good for smaller stems
Soft wire ties are much stronger
The stems you bend over with LST can be tied to weights, to the pots your plants are in, your hydroponics bucket, or most anything. It's wire, so it can be easily hooked around branches without having to tie anything and get your hands in the plant.
Now take a look at this harvest pic to see how this was achieved with LST
LST allows a more even distribution of light and the the whole stem of the bend plant will get equal access to the light. Eventually all the buds on a bent branch will start growing upward toward the light. After initially bending your plant, especially if stems are damaged in the process, growth will be slowed for few days as the plant recovers.
In addition, one of the natural reactions to being extremely bent over is the marijuana plant will stop trying to grow upward as much.
Low Stress Training Encourages Plants to Grow More Wide and Bushy
As a result, all the lower branches will start getting more bushy.
Some growers also gently bend flexible branches until they snap slightly or crush the bent part between their fingers to cause slight damage to the bent point. This technique is known as super cropping, explained below.
Manipulating your plant with bending or super cropping causes the entire plant to naturally grow more bushy, while you're also controlling the parts of the plant that aren't growing the way you want.
Basically you're training the plant to grow into the shape you desire, like a marijuana bonsai tree. You train the plant slowly and take care not to hurt you plant. You don't want to snap any of the branches, and never try to bend stiff branches or they'll just break off.
If you accidently hurt the plant, and you create an open wound, it's important to tape up the wound to keep it closed while also providing support to the stem. The tape acts like a bandage and cast for your plants wound.
If you wound the outside of a stem while bending, tape it up immediately! Most of the time your plant will recover just fine.
By using this method alone, you can grow a plant that conforms to nearly any shape that you want.
Supercropping (Extreme LST/Bending)
Supercropping is basically a more extreme version of LST/Bending. While it doesn't involve actually cutting your plant, it does involve inflicting some damage.
Supercropping can be used on all cannabis strains, but it is not recommended you use this technique on auto-flowering strains, as their lives are too short to recover from supercropping.
If you're growing two strains of marijuana, and one tends to be taller than the other, you can bend over the taller one as much as 90 degrees so that it is the same height as the shorter plant. However, a lot of stems are too stiff to easily bend over.
When this happens, you can crush the 'joint' between your fingers to get your plant to conform to the shape you want, and tie the branch down. This is known as "supercropping".
If the outside of your stems get damaged in the super cropping process, it's important to use electrical tape or duct tape to "bandage" the wound and give the plant time to heal. Never leave an open wound on your plant - the stem is more likely to die and your plant will be more prone to problems or diseases. Using tape will also give the stem support while it heals.
Most growers want to avoid the Xmas Tree shape because it's hard to get light coverage and instead encourage a plant to grow with more of a flat plane of buds.
In the above situation, using LST instead of topping the plant will save a lot of time compared to topping the plant to make it shorter
After supercropping, it's normal for the supercropped area to grow a "knuckle"
Bending, supercropping, and low-stress training are great ways to maximize your marijuana yields when you have a small amount of vertical room.
Sea of Green (SoG)
The term "SoG" (Sea of Green) refers to a cannabis growing technique where the grower uses a "sea" of many small plants grown naturally instead of trying to use other techniques to keep plants short.
To addanother confusing term into the mix, ScrOG (Screen of Green) is something totally different, and involves using a screen to grow a flat canopy of buds.
Here's an example of SoG in Action
Thanks to GIVE_ME_ATTENTION for making this moving gif of a SoG in action!
When using SoG, it's up to you to decide how many plants, and how big you let them get before you switch to the flowering stage.
Some growers flip to flowering when plants are just a few weeks old and a few inches high. Other growers may wait a bit longer to achieve bigger plants.
Here's an example of a small SoG setup
Flowering was initiated right after the above picture. Here's those same plants a little over a month later, after they've started making buds...
Notice how much taller the plants are at this stage. In a SoG setup, make sure you don't underestimate how much your plants will stretch after being switched to the flowering stage!
SoG setups are sometimes popular with those growing many auto-flowering strains, since these strains cannot be trained with most of the traditional plant training methods found on this page.
In some parts of the world, SoG isn't as popular as other training techniques because growers have legal limits on how many cannabis plants they can have at any one time. SoG uses a lot of small plants instead of training fewer big plants to fit your space.
But for those who are able to grow as many cannabis plants as they want, SoG may be a fast choice to get an even canopy and a lot of buds with very little plant training.
Screen of Green (ScrOG)
The term "ScrOG" (Screen of Green) refers to a marijuana growing technique that uses a net or wire mesh to control the height of the plant.
Warning! Never ScrOG unless you know that all your plants are female!
If you hear or read growers refer to "SCROGing," "scrogging" or "scroggin" a plant, this is what they are talking about.
To add another confusing term into the mix, SoG (Sea of Green) is something totally different, and involves growing dozens or hundreds of very short plants.
Example of a ScrOG Setup
When using the ScrOG technique, it is important to use a material for the screen that will be easy to take down after it's been filled by plants. In the above example, you can see a version of a screen that is easy to work and re-usable. The grower lined a square of 2x4's with eye hooks and used string to make the screen.
Possible Screen Materials
Below are the 4 main ones screen materials used:
1.) STRING - The very best. Laces up quick and easy and you just snip, snip, snip come harvest time. Throw it away and lace up a new one.
2.) Twine/hemp cord - Pretty much the same ease of use as string but you get hairs in the buds from fraying.
3.) Plastic fencing - works well but is kinda sloppy looking.
4.) Chicken wire / fishing line - The 2 worst
Chicken wire is terrible because the buds actually grow into it and you have to “cut” your harvest out. Snipping up chicken wire into a bunch of smaller pieces sucks, you get poked a lot and is an overall nightmare compared to string. Does it work as a screen? Quite well, but chicken wire sucks to remove.
The fishing line is also bad news as it can cut a stem very quickly and easily. Consider fishing line to be “sharp”. I have only used 12 lb test, I imagine something in the 30+ range might work pretty good though. Avoid any “braided” fishing lines especially.
ScrOG in Action
The point of a ScrOG is to first "fill in" the screen with plants during the vegetative stage. Without this "filling in" period, ScrOG is much less effective.
Here's pictures from ScrOG expert, ogkushog:
The first two to three weeks of flower are probably the busiest for pruning and lollipopping and also pretty critical as this is when you take the framework you sculpted in veg and really get your final canopy shape dialed in. I'd say during this time a grower might spend 1-2 hours per night just on pruning/lolipopping and rearrangement of colas.
During the fourth week of flower the time spent SCROGING tends to wind down when the colas' final stretch is nearly done.
This diagram should help you understand what a proper ScrOG looks like...
Group B - These are NOT Scrog
The following picture has a beautiful under current, but this is not a Scrog. Skeletal support at best, but again, not an example of a real Scrog.
Cutting Cannabis For Better Structure: Topping & FIMing
Topping and FIMing are two cannabis plant training techniques that involve "pinching" or cutting off some of the top growth. These techniques are designed to give you a free way to achieve better plant shape (to make better use of the available light), create more colas, and achieve bigger yields.
Topping: Cut top of plant between nodes
FIMing: Pinch newest growth (but not between nodes)
All plant training techniques are designed to help growers get a more desirable plant shape and bigger yields without changing other aspects of their grow. For example, cannabis plants don't naturally grow in a way that takes full advantage of indoor grow lights - a lot of light is wasted when cannabis plants are allowed to grow naturally without training.
Because of this, cannabis plant training techniques (like topping and fimming) are especially effective at increasing yields in indoor grow setups. Topping and FIMing are very similar to each other in that they create a bushier plant with extra colas, but they do have some differences.
Notice how these plants have many colas instead of just one - this is due to topping and FIMing
Note: The unfortunate acronym "FIM" stands for "F*ck I Missed," and refers to growers accidentally pinching off top growth instead of fully topping the plant between nodes. FIMing has become known as a technique of it's own since it has slightly different results compared to topping (recovery time, number of colas produced in one cut, etc).
These Techniques Should Only Be Used During the Vegetative Stage of Growth! Never Cut Your Plant While It's Making Buds
As far as methods that involve actually cutting the plant, you have two popular options. One is to 'top' the plant and one is to 'FIM' the plant.
With both techniques, you remove some of the growth on the end of a cola of a young marijuana plant, which causes the plant to stop focusing on one cola (like a Christmas tree) and instead to create many bud-laden colas (grow more bushy).
This will give you an idea of how the plant growth patterns change as a result of topping or FIMing at a young age.
Topping Your Cannabis Plant
When topping your cannabis, you cut off a growing