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How to Train Your Cannabis Plants for Better Yields and Potency

October 20, 2016
The underside of a marijuana plant's leaves in a grow room.
Whether your garden is big or small, outdoors or indoors, training your cannabis plants will greatly increase the quality and yield of your grow. Techniques are divided into two categories: LST (low stress training) and HST (high stress training). LST does not involve directly damaging your plant, while HST involves breaking or removing parts of the plant.

The goal of these training techniques is to alter the chemical balances in the plants. If left to grow naturally, cannabis will choose to produce one main cola (the topmost bud) that will reach as high as it can, but this is not optimal for yield and quality. In an indoor garden, you can only bring the light as close as the top cola allows. Buds found lower down on the plant receive less light. Training your plants properly, however, will allow for more even canopies.


Cannabis anatomy: The parts of the plant

A cannabis plant’s growth is dictated by a plant hormone called auxin. In cannabis plants, auxin is highly concentrated at the top of the plant, which prompts the plant to focus most of its growth upwards through the main stalk. Training techniques are used to reduce this focused upward growth and encourage the growth of a level canopy with an increased number of colas.

Here, we’ll show you how to train cannabis plants using these two types of methods.

Low Stress Training (LST) Methods

Low Stress Training (LST) your cannabis plants
LST generally requires more time and effort, but will significantly improve your cannabis crop. A common training technique for indoor grows, LST can be used on plants in either vegetative or flowering stages. There are two types of low stress training methods to know about, low stress training and screen of green.

LST (Low Stress Training)

This method shares its name with the style of training, which can be confusing when first learning training techniques. The LST method involves bending the plant as it grows, tying branches down that are becoming too long. When the top of the plant is pulled downward in a loose ‘L’ shape, auxin is distributed more evenly in the plant. As the plant grows, continue to tie down the top, resulting in more of the hormone auxin being distributed.

To tie down the plant, you can use green plant tape which can stretch to prevent the plant from being choked off. The end goal is to have the stalks of the plant snake around the pot, exposing a large number of bud sites at a level height. Once the plant enters its flowering stage, the colas will then sprout upwards from the sideways plant and produce an even level of healthy colas.


When is the right time to harvest cannabis plants?

SCROG (Screen of Green)

Similar to LST, the screen of green (SCROG) method involves using a screen to create a canopy. Instead of tying the plant down, you wait for the plant to grow through the screen. Once the branches begin to make their way through, you simply tuck the branches back down into the screen, essentially weaving the branches around it. When it comes time to flower, you will have a well-supported garden that will produce more even colas.

High Stress Training (HST) Methods

High stress training (HST) your cannabis plants
These HST methods are much more useful for large outdoor gardens than LST methods, and they generally require less time and materials. Although HST should primarily be done in the vegetative state, “super cropping” can be done early on in flowering, but stressing your plants during flowering is not recommended.


Topping is a simple HST method and requires no tools besides your fingernails. The goal is to remove the top of the plant, which will result in the top buds turning into two new branches. Additionally, it sends a shock to the rest of the plant that promotes growth in the lower branches.

This process can easily be repeated multiple times as the plant grows in its vegetative state. It will produce a well-rounded, healthy plant with numerous colas.

FIM (“Fuck I Missed”)

A more complicated version topping, FIM involves removing a very specific amount of the top portion of the plant. By scoping out only the topmost region of the new growth, the goal is to produce four off-shooting branches instead of two. Because of the complexity, this method takes significantly more time. It also puts your plant at greater risk of infection because you’re no longer making a clean cut on the stalk of the plant.


How to Prevent Root Rot, Mildew, and Leaf Septoria on Cannabis Plants

Super Cropping/Stem Mutilation

Stem mutilation is a more aggressive version of LST. Instead of tying down the top of the plant, you’re bending the branch until the fibers break and it folds over. The goal is to not snap the branch or even tear the skin of the stalk. You simply want it to kink and bend over.

To best do this, find the location you wish to break the branch and begin to roll and squeeze the stem. You will able to feel it weaken and break down, and it will eventually be able to fall over. This method will give the rest of the plant more exposure to light and time to catch up to this top stalk.

What other tips do you have for cannabis growers looking to increase yield and potency? Leave your best advice in the comments section below!

Trevor Hennings's Bio Image

Trevor Hennings

Trevor is a freelance writer and photographer. He has spent years in California working in the cannabis industry.

View Trevor Hennings's articles

  • Diab

    I’ve been closet growing for years and it’s not so
    Easy as to everyone being capable of doing it. Most people will find it frustrating and quit after a bad yield or no
    Yield at all.
    However, the true greenthumbs can find that it is an enjoyable and fruitful thing to do for very little money.
    The first time I tried, I used a bag of potting soil and a 5 gallon bucket and 1 seed of “tiger stripe”. 4ft. Shop light and some aluminum foil and total cost was $20.00.
    The plant went crazy and blew up to 5″ tall and crystallized like it was dipped in a vat of sugar.
    Green thumb or beginners luck?
    I yielded maybe a half ounce of some crazy weed. Not too shabby for a beginner. Not too shabby for a pro when you compare the THC content and looks.
    Sometimes though I’ve used an elaborate setup and failed miserably and for you beginners, whatever you do don’t use organic manure indoors. It’s a GNAT colony waiting to hatch. And if you got gnats, use a cup of dawn dish detergent. It’s tried and true.
    So growing cannibus is good for some but not for many.
    If you want to try it read up watch videos and start small then build up as you get more comfortable with it.

    • Jan-Willem van Bremen

      Hey, I was wondering about your statement about using organic growing medium indoors. I’ve done that and I’ve gotten a Gnat infestation, next grow I wan’t to grow again preferably using the same soil (I got a lot of it and it’s high quality organic soil). Is there any way I can ‘sterilize’ the soil of Gnats, worms etc. by freezing/heating/drowning it or anything. If not can your cannabis still be considered organically grown when not using soil advertised as organic?

      Thanks in advance!

      • Diab

        Yes that’s a common problem when using organic soil on indoor grows.
        The easiest solution is to find a shallow cup or plastic container with a large surface area and add simple dawn dish soap original liquid. Blue in color or orange works too. Set cup with about an inch full of dawn next to your plants and wait.
        The gnats Love dawn and will fly onto the dawn liquid and die. Within a day or two you’ll have killed almost or all the gnats.
        Organic soils use a lot of manure which the gnats seed with offspring. They dry up and lay dorment until you water your plants. Like a seed they soak in the moisture and hatch.
        Now keep in mind “organic” technically means 7 years or cycles without any chemicals added to it, but, you’ll need a PHD in chemistry to know if in fact that soil is truly organic as there’s no rules to guarantee the sellers of soil are being truthful. Most likely they are but who’s going to verify?
        The dawn , gnat killing ideal works better than anything on the market but it only works after the gnats are present as I’ve added Dawn dish soap to my soil mixes and although the plants love it , the chemicals in dawn aren’t what kills the gnats. It’s the sticky surface that kills them, basically the gnats drown as they can’t get free once they fly into the dawn liquid.
        Plus, it voided the Organics of the grow.
        Unless you have an elaborate setup with Co2 or go chemical based soil you may have to resort in treating the infestation of gnats during the veg cycle like I do.
        Hope it helps.

        • Nick Kiefer

          I’m guessing you were on a sativa when you wrote this. 😀

          • blackpewdiepie “saving u money


          • Diab

            Indica sativa hybrid lol

      • DannyShevlin

        Load it up with diatemaceous earth,.it breaks the gnats life cycle.beneficial nematodes are great when used with it too.I did it and it worked for me.

      • Larry

        Easiest way to deal with gnats is keep the top inch or two of soil dry. Moist soil, manure, or compost are breeding grounds for gnats, fruit flies and spider mites. Yellow sticky cards are messy to deal with, but attract gnats.

      • Christian Tonello

        You could stew/boil it in some DIY garden boiler. BUT. There’s one other thing worth mentioned: Nematodes SF. These nematodes kills the F.Gnats in his larvae stage. You can use Sticky Traps for the adult Gnats, The nematodes SF will take care of the larvae so that you have only one last generation of adults to get rid of. GL!

      • Trichos_999

        Pasteurization. Not too hard to achieve with a cheap DIY water boiler in the garden. 2 Metal buckets which fit into one another. The upper one with a wholly drilled bottom, to let the steam come through but hold your potting-mix in place. In the bottom bucket you boil water (quite obvious I know…) and then place the top bucket half-filled with soil-mix on top of the boiling one, they should fit tightly. If you have the space and possibility, following steaming with 3 weeks of freezing at minimum -5°F. (The lower the better). Stewing time really depends on how much soil-mix you’ll put in the DIY, how well does your DIY keep steam and temperature, what is your soil-mix, etc…If you have a big bucket and a proper bonfire you can fill the top bucket (but always leaving the soil-mix as airy and fluffy as possible) and leave it goin’ for 5-6 hrs. If you need 4 gal for some seedlings it’ll be ready in 2 hrs. Theoretically the whole mix should reach 212°F for 1 hr roughly. But keep in mind that every inch of the inner material in the bucket should reach that temperature for that length of time, which means you better leave it for much, much longer as the centre part will take its time to reach desired temps.

        Possibility n.2 “Sun Pasteurization”. thick plastic sheet laied on the bottom in the sunniest side of your backgarden. Scatter your soil-mix evenly on this layer of plastic. Cover it with another layer of the same thick plastic. Carefully up-fold the two layers so that what’s inside, stays inside and the other way round. If you have 75°+F and sunny days you are good in 2 weeks. If it’s winter and cold but sunny give it 1 month.

        @Danny Shevlin suggested “diatomaceous earth” and Nematodes SF.

        D.E. works a wonder! If you don’t know what it is I advice some research, youtube has plenty infos on this incredibly useful thing we incredibly know so little of! It’ll help you out with plenty of insects and bugs (and if you buy the “food grade” you’ll have it for 1000’s purposes more). Nematodes SF work great too but do better in conjunction with something else (like D.Earth!).

        The very big difference is that through pasteurization and a clean & tidy op. with extra care with pets, grow room cleanliness, correct watering, watch out for hitchhikers (if you go for a stroll down the woods you’ll easily get some “passenger” back home who will enjoy the ride to your clean grow room) you might hope to grow “pest free” or kinda. The other solutions are ok and can be used to prevent too, but usually come to our attention only after the infestation began.

        GoodLuck Happy Cultivar!

    • Danny Carbona

      5 inches tall, eh? That’s a teensy plant.

      • Diab

        Haha yeah that would be. Then again most readers know what I meant. Nubby thumbs and all don’t help when typing on a phone:)

        • Danny Carbona


        • blackpewdiepie “saving u money

          5 inches or feet?????

    • “And if you got gnats, use a cup of dawn dish detergent.”

      Should I drink it or what?

      • Diab

        Sure but only half . Leave the other half in a shallow glass or shallow patry dish and all the gnats will fly into it get stuck and die.
        It’s an unusual and great trick to get rid of them.

  • Len Russell

    The author is incorrect. His description of “Sea of Green” (SOG) is actually what’s referred to as “Screen of Green” (ScrOG). Sea of Green is a technique using a large amount of small plants stacked close together, each with one small main cola. The intent of SOG is that each plant will yield a small amount, but there will be larger total yields due to the larger number of plants.

    I grow ScrOG because I’m limited legally to four plants. I spread each plant over a 5′ x 5′ screen with a 1,000 watt light, and yield at least two pounds of top shelf bud per plant. It’s a very labor-intensive technique, but the yields and the quality are worth it.

    • Mike Morrison

      You obviously did not finish reading his article!

      • Ken Gouge

        “You obviously did not ——- read— his article!”

    • Dennis Embree

      I just came across your post about using a ScrOG. To a newbie, living on a fixed income, would you know what would be the best place to do research on growing. I have a 4x4x6 grow tent and a 1500w LED light so far…getting piece by piece and could really use some help to save cash, but growing the most for my space, and of course my ability…again, I’m a newbie! Thanks

      • Paul

        You should check on the space requirements for LED lights. After paying a lot of money for one, I discovered that LED lights require a lot of space between the light and the top of you plant. The leaves at the bottom were all drying up and falling off. I have more space than your 6′ high tent.

  • Paul Sorensen

    Oregon went legal to grow and consume rec in Oct. of 2015. I hadn’t grown since 1973, when I had a light/timer set up in an appliance box in the closet.
    Jump to 2016…I got everything I needed to grow indoors on Amazon. I planted the clones in March, and used the 12-16 lighting method. I grew two strains: Lavender and Banana OG. The grow box I bought on Amazon worked great. My biggest mistake was using the wrong potting soil. I battled gnats and spider mites. The organic treatment I used didn’t solve the problem completely. I was ready to throw the Lavender out. My wife took it out of the box, cleaned it up and planted it in the garden, where it flourished. I did a harvest of both In July. I left enough leaves on the two plants to allow them to put out fresh growth. This time, I put the Banana OG in the garden with the Lavender. Nature controlled the light on the second grow. I got my second harvest of both on Oct. 10. Next time I’ll use Happy Frog soil (better drainage), and I’ll pinch the tops to get a better yield. So, to get two harvests, grow indoors AND outdoors.

  • potmaster

    These recommendations are pretty good. I was at Oaksterdam U. when Kyle Kushman taught his first class. The bending method that he taught was called “Chiropractic.” He very aggressively bent all of his demo plants. The staff audibly gasped and after the class the plants were put in plastic bags and removed from the property. The first time one sees this method one can be shocked. All of the side branches normally turn upward. By gripping a branch with both hands and twisting one will hear a pop and bring the branch to the horizontal. It does work for productivity. It will give greater production because more of the plant will receive sunlight. Some of the things one needs to do are to clean the inside 50% of a branch and the other thing is to remove any branch that has a diameter that is smaller than at the other branches. The plant has a finite ability to produce. By inspecting the plant and looking for and removing those buds that are not developing at the same rate as the the larger buds you will have a better crop. As far as the Auxins are concerned, at the only way I have ever been able to grow a plant without side branches has been to stress and starve the plant. Out doors, without pinching or FIM, I have grown plants with side branches up to nine feet tall. The production of product on those branches exceeded 300 grams and plant productions up to thirteen pounds. I have tested and have found that one gets less production if one uses these methods.

    The secret of having a healthy plant and great harvest is to have available to the soil all of the nutrients needed for maximum quality and quantity. ( I am only talking about organic /OMRI grows) One must understand that the soil is a living organism. One must address the needs of the soil in order for the plant to have the elements (nutrients) needed for maximum health for the plant. Remember the living organisms have to eat the organic material and break it down so the plant can absorb it. The soil is actually the stomach for the plant. The plant, like us, can only absorb the nutrients after they have been released by the biosphere.
    There is a lot more to this subject then can be said here. Remember if this is your first time, write down what you are doing and observing. After the harvest talk to another grower or your Collective about what you have done. Farming (growing) is the only profession where God works for you. You prepare the soil, plant the seed and pray.

  • wes yampakid

    high amounts of co2 will kill gnats,good luck, $45.00 ozs in denver 13 dollar shatter grams i don’t have to grow now!!!!!!

    • it’s so true….

    • Shawn Fitzsimmons

      Damn Prices here in Ontario are like 35$/Shatter Grams and 200$ AAAA flower Oz. Only pray 1 day prices here drop to that yampakid LOL

    • blackpewdiepie “saving u money

      damn what are the prices per oz now

  • Simensen Says (Go witha flow p

    When flowering, set up a cag of yiest for alcohol beveraging(!) it produces lots of CO2 which makes the plant take of in the process.

    Try, and you`ll be surprised.

  • briteleaf

    I only grow auto’s outdoors but I take floral training wire and cut it into about a straight 9″ piece. I fold it in half to make a stake and stake the young plant down into a horizontal position exposing the side shoots that will come from each node. and continue staking down the main stalk and the side shoots into the first week or so or beginning bloom. The plant will end up with lots of colas that all grow up together. It keeps the plants short but maximizes the auto grow usually in around 80 days from seed. Twist and tuck shade leaves to expose side shoots to more light.

  • Red4Life

    i had a gnat problem. I cut up fly strips and placed them in yellow yoghurt pots. 1 per plant. Theres soooo many stuck now, and havent seen 1 in weeks. Its messy getting them into the yog pots, but so easy to remove them to water the plants and then replace them back in.