How To Perform Low Stress Training On Cannabis For Better Yields
Low stress training (LST) is a growing technique that involves manipulating the shape of cannabis plants to produce better yields. It’s easy, and can actually be a lot of fun to do! Read on to learn how to LST like a pro!
Even if you don’t have a lot of cannabis growing experience under your belt, you should still consider giving low stress training a try. Low stress training (LST for short) is a simple and methodical way to increase your yield while controlling the height and shape of your plants.
WHAT IS LOW STRESS TRAINING AND WHY DO WE DO IT?
As a yield-boosting training method, LST allows growers to make the most of their available space and light. At its simplest, this training technique involves gently bending and tying down cannabis plant branches and stems. We do this for two reasons: First, cannabis normally grows one large main stem that develops one large, elongated cola. This exists alongside other, smaller side-branches with smaller buds to suit. The natural tendency for cannabis to grow into this “Christmas tree” shape is known as apical dominance. With LST, the goal is to break this apical dominance, instead flattening out the canopy to grow at the same height.
This brings us to the second reason behind LST: better light distribution. By bending and securing plants in a way that breaks apical dominance and evens the height of the canopy, all areas of the plant will be exposed to greater light distribution, thus creating more viable buds sites and larger yields at the end! Not only that, but LST doesn’t even require you to alter your growing setup to achieve great results. All you need is some know-how and a few essential tools.
THE HISTORY OF LOW STRESS TRAINING
If you’re familiar with growing cannabis, you’ll know that plants normally develop a few fat buds toward the top of the plant, with several smaller buds below. This is not only true of cannabis, but many other flowers, fruits, and veggies used by humans.
Over centuries, horticulturists have devised ways to get more out of their plants using simple training techniques. These techniques can involve topping and pruning plants, as well as bending, ScrOG, and all manner of other methods. Although they all differ slightly, each one ensures optimal use of light, space, and resources.
Low stress training is a modern variant of an old technique used to force fruiting trees to grow in a flat structure. The ancient Egyptians are thought to have used similar methods to grow fig trees horizontally more than 3,000 years ago. A method known as espalier then became very popular in 17th century Europe, and made espaliered (ie. carefully trimmed and shaped) hedgerows of fruit trees a common sight. The practice was also widely used in apple and pear orchards—not just for better harvests, but more so as a way to beautify the landscape.
LST: A TRAINING TECHNIQUE THAT YOUR CANNABIS PLANTS WON’T MIND
A key element of this training technique lies plainly in its name; “low stress” is what separates this method from “high stress” techniques like topping. Whereas the latter technique involves cutting off the plant’s main growing tip in an effort to redistribute growth hormone, LST is much gentler. Not only does this decrease the risk of over-stressing your plant, but it means less time spent waiting for your plant to recover and adapt to high stress changes. With LST, there’s no inherent pruning or trimming, although this method is often used alongside other, more severe tek. All in all, plants that undergo LST respond very favourably, and will reward you for your efforts and finesse with healthy, hefty yields of huge buds.
WHAT YOU NEED FOR LST
To properly perform LST on your plants, you need the following equipment:
- Rubber-coated plant wire/soft plant ties
- Thin wooden/bamboo stakes
- Small hand drill
- Duct tape
Although this method requires little supplies, we seriously advise against using regular string to hold down your plants. Regular string or wire is often too thin or harsh, and will cut into the stems and do more harm than good. It’s much better to seek out special plant ties suited for the job.
PREPARE YOUR CONTAINER FOR LST
We keep referring to tying down stems and branches, but to where?! All you need to do is drill several holes around the rim of your growing container. Now you can loop the ties through the holes and around the branches to hold the shoots securely in place.
For even more support options, some thin wooden or bamboo stakes with a length of about 30cm work great to hold everything in place. And lastly, because accidents can happen when we’re bending branches, get some duct tape so you can patch up any snaps or breaks.
HOW TO LST YOUR CANNABIS PLANTS
Let’s get to the interesting bits: how to LST your cannabis plants!
BREAK APICAL DOMINANCE
To start, it’s all about breaking that apical dominance. Begin by bending your main stem gently down toward the rim of the container. Using the soft plant wire and the pre-drilled holes, securely tie the stem in place. Ta da! You’ve just flattened the canopy and made way for future, horizontal growth. This way, light will reach many more buds sites, which in turn will result in a greater yield.
Tips: Some growers choose to first top the main stem, then bend the secondary shoots out to the side. This way, the plant will take on more of a “spider” shape. But even if you’re performing standard LST—without topping—you may want to consider some light defoliation to increase light penetration.
SHAPE AND MAINTAIN YOUR PLANTS
One thing to keep in mind with LST is that you always want to maintain a flat canopy, so no one branch is taller than the other. When it comes to shaping, it’s important to bend shoots outward and away from the main stem. This isn’t rocket science per se, but it is helpful to have a desired shape in mind rather than just winging it. Even this can work, but beginners are better off doing some basic planning to avoid any pitfalls.
Moreover, sometimes accidents can happen, say if you accidentally snap a branch as you’re bending it. No reason to freak out! Plants are actually more robust than one may think. As long as a branch hasn’t entirely come off, you can always fix such mishaps with some duct tape. It will take a week or so to heal, but it won’t be the end of the world.
Likewise, know that LST isn’t something you do once and then you’re done. This technique requires consistent upkeep. The reason for this is that your plant will keep growing regardless of what shape you’ve moulded it into. In time, shoots will grow and leaves will get larger. For this reason, you’ll want to re-adjust your bends once in a while to make sure the canopy stays nicely even.
WHERE AND WHEN TO LST
Some people think LST is for indoor growers only—but this is far from true! Don’t forget, plant training isn’t exactly new, and it began as an outdoor method to boot. If you live in a colder climate such as the UK and other parts of Northern Europe, outdoor LST can be a good way to increase yield during the summer season, even if you’re not blessed with much sunshine. Likewise, LST can also be a helpful tool to keep your outdoor cannabis plants low-profile. A plant that you tied down for a flatter canopy won’t just give you better yields, but will also draw less attention compared to a towering weed plant somewhere out in the wild, just waiting to be discovered!
As for when you should start with LST, the answer here is: as soon as possible. Once your plant is comfortably in its vegetative stage, it will be primed and ready for manipulation. You don’t want to go too early before the plant has established a few good nodes, but you also don’t want to wait around. There is only one time where LST can be genuinely problematic, and this is when your plant is already into full flowering. At this stage, the plant’s stems may be too rigid to bend, and you risk potentially snapping a branch holding your precious buds. This aside, however, you can start LST at pretty much any time during the vegetative phase. The earlier the better.
WHAT ABOUT LST AND AUTOFLOWERS?
Can you LST autoflowers? Absolutely!
Autoflowers grow quickly and don’t require a change in light cycle to initiate flowering, meaning they don’t have much time to recover from high stress training methods like topping and defoliation. With LST, however, plants can still benefit from the optimal light exposure, and they won’t need time to recover since it doesn’t cause any real damage. Although the autos of old likely would not hold up well to LST, the new generation is more than capable of handling it.
In fact, LST can be a great way to boost the yield of your autoflowering ladies! Just know that autos will go into flowering after about 4 weeks, so you should have already made up your mind whether you want to LST them or not! Get started as early as possible for best results.
Here are the top 5 strains to utilise the LST method with:
Chocolate Haze is an absolute treat for the taste buds, with hints of chocolate, sweetness, and earthiness lighting up the tongue when smoked or vaped. The unique terpene profile within the flowers was gifted to this strain via the breeding of parent strains OG Chocolate Thai and Cannalope Haze. Chocolate Haze is a sativa-dominant lady that features 95% sativa genetics and just 5% indica genetics. This results in a potent high that is cerebral, motivating, and very energising. Fuelled by a THC content of 20%, this high takes hold fast, and is often the source of some very interesting and deep conversations.
Chocolate Haze can be grown successfully both indoors and outdoors, and is a strong contender for the LST method. Indoor plants cultivated within grow rooms or tents are capable of rewarding growers with yields of between 475–525g/m². Outdoor plants grown within garden beds or pots are able to produce harvests of up to 500g/plant, and are ready for harvest during late October. Chocolate Haze favours a mild climate and features a flowering time of 9–10 weeks.
Want to increase your yield? Click to learn how to perform Low Stress Training (LST) on your cannabis plants, then watch them pump out copious amounts of bud!
How to Train Auto-Flowering Plants for Bigger Yields
How to Use Plant Training Methods on Auto-Flowering Strains
For those who don’t know: An auto-flowering marijuana plant automatically starts making buds about 3-4 weeks from germination, and most plants are ready to harvest by the time they’re 3 months from seed. Auto-flowering strains produce plants that are ready to harvest earlier than almost every “regular” (photoperiod) strain and don’t need special light schedules. You generally only get auto-flowering seeds from a reputable breeder.
A Sweet Afghani Delicious (S.A.D.) Auto at 5 weeks old and 15″ tall – just a week away from harvest!
The quick-yet-bountiful harvest is one of the biggest benefits of growing auto-flowering marijuana plants. However, the shortened vegetative stage brings up an important question. Generally, when growing “standard” (photoperiod) strains, indoor growers use plant training methods for the first 4-6 weeks of a plant’s life to make plants grow flat and maximize yields in the flowering stage.
Can auto-flowering plants be “trained” in their short vegetative stage? And if they can be trained, does it actually provide any benefits? The short answer is “yes” to both questions (with one caveat)!
As Long as Plants Are Healthy, Auto-Flowering Cannabis Strains Usually Respond Well to Simple Topping or Low Stress Training
This gorgeous Hubbabubbasmelloscope auto-flowering plant was topped at a young age by a talented grower called awolace (who has many great grow journals on auto-flowering plants) and produced 4.75 ounces by itself.
Auto-flowering strains can be trained to produce more and bigger colas, and proper plant training can increase yields and overall improve your grow results.
Auto-flowering strains from a decade ago were heavily hybridized with wild hemp and produced small and subpar quality flowers. However, modern auto-flowering strains from trustworthy breeders (like this Auto Lemon OG Haze plant from breeder Nirvana) produce buds that are just as potent and beautiful as traditional photoperiod strains.
3 Main Schools of Thought on Auto-Flower Training
There are 3 main schools of thought about what works best when it comes to training auto-flowering cannabis plants:
- No Training at All – Since autos only stay in the vegetative stage for a few weeks, if you stress your plant too much with extensive training, it may end up stunted. A stunted auto-flowering plant produces very low yields. As a result, many growers recommend no training at all when it comes to auto-flowering marijuana strains, just to be safe. Untrained plants still produce a lot of bud!
- Low Stress Training Only (Bending) – The idea behind low stress training is to force the plant into the flat shape you want by bending all new stems and tying them down. The advantage of sticking only to bending is it’s very low stress (hence the name) on the plant. There’s basically no chance of stunting from simple bending. However, with LST you don’t have the same full control over the plant’s shape as you do when you actually “top” the plant (split the main cola into two), which makes it very easy to grow a wide and flat plant.
- “Top” the Plant in Addition to Other Training – Modern auto-flowering strains often respond well to “topping”. This is when you cut off the very top of the main stem when the plant has only a few nodes, so that it grows two main stems instead of just one. This makes it easy to spread out the plant under the light. Topping usually won’t stress your plant if it’s healthy and fast-growing, but it’s possible that topping may contribute to stress or stunting if your plant is slow growing or sickly.
Most growers agree you don’t want to do aggressive training on an auto-flowering plant, for example you probably wouldn’t want to make a full manifold, which takes several weeks in the vegetative stage to set up. Though there are exceptions, you usually don’t have enough time in the vegetative stage to take full advantage of that kind of training technique with auto-flowering plants.
Example of a Stunted Auto-Flowering Plant
These auto-flowering plants were stunted when they were young by heat and overwatering. Now they’ve already started flowering and are just a few weeks from harvest.
Even though they have a plentiful amount of light, at this point the plants are not going to get any bigger no matter what the grower does because the vegetative stage is over, and the flowering stage is already under way.
Here’s a closeup of the middle plant. You can see by the bud development that it’s just a few weeks from harvest. Since it’s this far into the flowering stage, you know that the plant is not going to get any bigger. The buds will fatten up, but even if they tripled in size, the grower would only get a few grams of bud. The plant just isn’t big enough to support bigger yields.
This is why many growers recommend no training for auto-flowering plants. They’re trying to avoid stunting. But in the above example, the plants weren’t even topped. They were stunted from heat and overwatering, not training. So, I think the main point is to avoid stressing the plant when it’s young, not something as black and white as “no training allowed.”
Untrained Auto-Flowering Plants
Here are examples of untrained auto-flowering plants. With good care and a lot of light, they can produce a whole lot of bud without any training, especially the medium to tall strains!
These 5 auto-flowering plants were started at the same time. Without any training, they grew into this sea of buds at harvest! Growing many untrained plants together can be one of the easiest ways to get to a quick, hefty harvest. This style of growing is known as Sea of Green and is very well suited to auto-flowering strains.
Low Stress Training on Autos
Here’s an example of LSTing an auto-flowering plant by bending over the main cola when it was young and still mostly in the vegetative stage.
This allows the plant to be spread out in a way that’s somewhat similar to the result of topping
This auto also wasn’t topped. I only used bending and securing to try to keep it wide with many colas. I was happy in the end with the shape, but it was a big pain trying to keep it flat. It’s just a lot easier to keep plants flat when you top them, since it splits them and you can lay each side flat.
Without topping you end up making a “spiral” with the main stem to keep it as short as the rest. Here’s the “skeleton” of that plant to give you a better idea of what the training looked like underneath
An auto-flowering Super Skunk plant just before harvest – this plant spent a little over 2.5 months under a Mars LED grow light.
A view from the side of the same plant. Only LST/bending was used to keep it short and wide, and as a result you can see there’s still one dominant cola higher than the rest, even though the plant has been completely bent over.
Topping an Auto-Flowering Plant?
If you cut off the very top of a young, fast-growing auto-flowering plant, it may not even notice. Many growers recommend against topping an auto plant because stress can stunt your plant. While you definitely want to avoid stunting, I personally think topping autos works well as long as you make sure your plant is healthy and fast-growing first.
To be honest, other factors like overwatering or a poor environment seem to be much more likely to stunt an auto-flowering plant than topping, especially if you’re cutting off just the very tip of the plant without removing much plant matter.
Overwatering or a poor environment is far more likely to stunt an auto-flowering plant than a simple topping. For example, this auto-flowering plant was stunted due to overwatering and heat.
I’ve seen that many growers in our forum (check out photos from Green75 for some great examples!) have gotten great results topping their auto-flowering plants. I’ve also seen many growers (myself included) get incredible results with either no training or just low stress training! So, I definitely think you can succeed with any training style as long as you listen to your plants!
This Auto Amnesia Haze plant was topped, trained and defoliated. It already has a sea of buds with a month left to go until harvest!
When is the best time to top an auto-flowering cannabis plant?
Although you can top a plant any time it is still in the vegetative stage, I believe you will get the best results by removing the 3-5th node while it’s still tiny, as long as the plant is fast-growing.
This is about as old as an auto-flowering plant should be for topping
I think one of the most important things to avoid stunting is to remove as little as possible. The less you remove, the less the plant will notice.
I personally wouldn’t cut off more than this when topping an auto-flowering marijuana plant.
You could even have pinch the stem off a little higher, above those two baby fan leaves. The arrows point to the two growth tips that would be the new “tops” if you had cut where the red line is. In this case, you would have removed even less from the plant, reducing the chance of stunting even more, and helping your plant keep as much growth as possible.
This diagram shows where to cut for topping, along with where to expect the new main stems.
When is it a Bad Idea to Train an Auto-Flowering Plant?
Auto plants are on a very tight time schedule in the vegetative stage, and therefore plant training isn’t necessarily the best idea for plants that are already sick or stunted since they likely won’t have time to recover.
Don’t Train an Auto if…
- Plant is Sick, Stunted, or Slow-Growing
- Plant is older than 4-5 weeks old and has already started forming little budlets – after this point only use low stress bending and securing to keep the plant the shape you want
With an auto-flowering strain, you generally have about a month to create the main shape of the plant. After that it will start flowering and although it will continue getting taller, you want to let the plant focus on fattening the buds as opposed to a whole lot of further training.
If you’re not sure whether to top your plant, it’s recommended to stick to bending as it can achieve similar results without any risk of further stunting your plant!
That being said, almost every other plant training method (topping or FIMing, low stress training, supercropping and Sea of Green) can be used on auto-flowering plants as long as you watch the plant closely for signs of stress and make sure you let the plant get big enough to produce good yields in the flowering stage!
Extra Growing Tips for Autos
Low to Medium Nutrient Needs
Whether you grow in soil, coco coir, or a full hydroponic setup, auto plants often tend to prefer relatively low levels of nutrients compared to many other cannabis strains.
When it comes to adding extra bottled nutrients, start at 1/2 strength of the recommended dose or less, and only add higher levels of nutrients if needed. In hydro use “vegetative” nutrients until you see “budlets” (little bunches of white hairs) which is often around 4-5 weeks. In good soil, you don’t need to add any nutrients during the vegetative stage. After the first signs of buds, start adding “flowering” nutrients at very low strength (1/2 strength to start).
Potted Auto Plants
Potted auto plants tend to do best in an airy potting mix with lots of drainage (plenty of drainage holes, and something like perlite to help add more drainage to your growing medium). This helps makes sure roots get plenty of oxygen so plants grow as fast as possible.
With any soil mix, it’s recommended to have about 20-30% extra perlite for increased drainage.
Strain & Final Size Have an Effect on Training
The final size of your auto plants is largely dependent on the strain you get. Some strains, such as Lowryders, have been bred to grow extremely short – less than 1-2 feet. Other strains can grow taller, up to 4 feet tall or even more.
Although most auto strains start flowering at just 3-4 weeks, some strains take up to 8 weeks (or even longer) to auto. Often, long-flowering auto strains are labeled as “Super Autos” or “XXL” but you should still read the breeder description to fully know what to expect as far as timelines and height.
If you have a plant that is not “auto-ing” as soon as you want, you can put it on a 12/12 light schedule and it will usually start flowering in 1-2 weeks just like a photoperiod plant.
These two auto-flowering plants are the same age and were grown in the same setup! Genetics makes a huge difference to your final results, so it’s important to pick the right auto-flowering strain! The small plant is White Widow Auto & the huge plant is Onyx Auto.
These two auto-flowering plants are also the same age and grown in the same environment. The small plant is Auto Chemdawg & the huge plant is Super Lemon Haze Auto.
As a general rule of thumb, auto plants tend to double or triple in size from when they first start showing signs of flowering/budding (usually when plants are about 3-4 weeks old from seed).
Final Height of Auto-Flowering Plants is Often
2-3 Times the Height When the Plant First Started Showing Pistils
An auto-flowering plant is usually “full size” at just 6-7 weeks from seed! For example, these autos are 6 weeks old and didn’t get any taller, even though buds are still fattening and harvest is still several weeks away!
A stunted autoflower won’t produce much bud because it never gets big!
Bend too-tall branches down and away from the center of your plant
Plant training is a tactic that helps cannabis growers increase yields indoors by exposing more buds to strong, direct light from the grow light.
When growing any cannabis plants indoors, it’s recommended to at least use bending to open up the plant so it grows flat and wide
A view from the side just before harvest so you can see how those plants were trained to grow flat and wide. Training allows all the bud sites to grow directly under the light, so they get as big as possible
Recommended Auto-Flowering Strains and Breeders
Which breeders can you trust for good auto-flowering marijuana seeds? These auto breeders have dedicated themselves to developing auto-flowering strains in particular, and have gained popularity for their consistency and quality.
There are many other breeders that offer auto-flowering seeds, but the breeders listed have become famous for breeding some of the best auto seeds when it comes to ease of growth, potency and yields. Let us know if you believe there’s an auto-flowering cannabis breeder we should add to this list!
Dinafem was one of the first breeders to go “all in” for auto-flowering strains when they started a comprehensive breeding program several years ago. Their award-winning Auto Sour Diesel strain produces average looking buds, but the strain was easily one of the most potent autos I’ve grown. In fact, every auto strain I’ve grown from Dinafem has produced above-average quality buds in smell, appearance and potency.
Auto Sour Diesel – bud look average but bud effects are unique and powerful!
Nirvana has several popular auto-flowering strains, but their latest auto strain Auto Lemon OG Haze has been getting some especially impressive results in bud quality, with a nice appearance, high THC and a medium amount of CBD. Their Auto Northern Light is another popular strain, especially with first-time growers, because it has a relatively low smell and is known for being easy to grow with good yields.
Sweet Seeds is known for colorful auto strains that are easy to grow, like their Dark Devil Auto and Black Cream Auto.
Examples of Different Possible Bud Colors on Black Cream Auto Plants
Over the last few years this breeder has really started becoming very popular for auto-flowering strains, and has made a name for producing amazing auto-flowering genetics. I’ve seen several beautiful examples of Mephisto Genetics in our forum but no one has formally submitted a picture yet! Send us your pics!
Is "topping" an auto-flowering strain ok? Does plant training increases yields? Auto-flowering cannabis strains actually respond very well to training as long as you do it right!