If you've always grown weed plants naturally and want to try something new, you might want to consider the technique called low-stress training (LST).
LST involves bending the main stem of your cannabis plants and tying it down to stay level with the other branches. This helps all parts of the plant grow evenly and get the same amount of light, plus it helps control the plant’s height.
Many growers enjoy LST because it boosts yields without needing new equipment and can be fun. LST can boost cannabis yields by as much as 25% compared to untrained plants.
However, if not done correctly, it can harm your marijuana plant. Ready to learn LST? This guide will help you get started.
The basic idea of low-stress training (LST) is to bend the main stem of a plant when it has four to six leaf nodes. Then, tie it down firmly but not too tightly to stay level with the smaller branches.
This helps the plant grow evenly. Tie it in a way that lets you move the plant around but keeps it secure enough to hold the stem in place.
LST is typically done during the vegetative phase when the stem and shoots are still flexible. At this stage, LST encourages the cannabis plant to grow circularly instead of straight up.
You can also use stakes anchored in the soil to tie the branches into the shape you want. Alternatively, you can use strings with weights to keep the main stem bent. There are intricate steps to carry out when doing these, which will be explained as we progress in this article.
What sets Low-Stress Training (LST) apart from other cannabis plant training methods is that it doesn’t involve cutting or removing any parts of the plant. This means it doesn’t stress the plant out.
As the plant grows, the main stem will start to grow upwards again, so you'll need to repeat the training process at any time during the plant’s vegetative stage.
However, once the plant starts forming buds, you should stop training because you want it to focus all its energy on producing flowers.
In the sections that follow, you will learn the step-by-step process of using LST on cannabis plants. But first, let's briefly discuss why this technique is important to ensure you're on the right track.
This leads us to the science behind LST and other training techniques you should familiarize yourself with, especially as they compare with LST.
Like many other plants, cannabis naturally grows with apical dominance. This means it grows straight towards the light Christmas tree shape.
Apical dominance is a survival strategy that helps plants grow directly towards the main light source for the best photosynthesis. The side branches at the bottom get less light compared to the top of the plant.
In a 2019 study, researchers discovered that removing the top bud can overcome apical dominance, preventing the growth of lateral shoots.
This allows more lateral buds to develop into additional branches that can produce more fruit and increase seed yield. The study tested this idea on five cannabis sativa cultivars over two years.
However, the science behind LST is to artificially manipulate this growing pattern without any stress on the plant.
Once you tie the main stem of your cannabis plant horizontally, the side branches will be exposed to more direct light from above.
This boosts their growth, making the side buds grow larger and yield higher. The great thing about LST is that it's easier to do than most other training techniques.
The LST method creates a uniform canopy, allowing all parts of the plant to get more light. This boosts photosynthesis and can lead to higher yields.
It also guarantees improved light exposure. This technique ensures all parts of the cannabis plant receive enough light, which is essential for healthy growth and developing buds.
If you’re growing indoors, LST helps control the plant's height. More importantly, the uniform canopy enhances airflow around the plant, lowering the risk of mold and mildew.
Meanwhile, unlike other training techniques like topping, LST is gentler and less stressful on the plant.
High-stress training (HST) is the training technique you’d use on a weed plant. It takes longer to rebound from these methods, but that isn't necessarily a bad thing.
Compared to low-stress training, high-stress training involves more risk but can offer greater rewards.
One such is supercropping, which involves bending and breaking the inner fibers of the branch to make it more flexible.
This reduces the plant’s height and encourages growth without damaging the outer part of the stem.
● It is best applied during the 18/6 light cycle or before preflowers.
● Encourages robust and thick growth and hardwood side branches.
● Increases production and resistance of the plants.
● It helps manage canopy height to make it ideal for limited growing space.
● It can be very stressful for plants.
● Risk of stunt growth or weak parts if recovery time isn’t given.
● Inexperienced growers may handle HST in a way that exposes weed plants to infections or growth issues.
And, of course, there’s the option of natural growth. This means you let the weed plants grow independently without shaping or guiding their development.
Of course, plants will grow just fine without any training and under the right conditions. However, this has benefits and downsides.
● You don’t need to spend time and effort on techniques like pruning or tying branches.
● It is more accessible for beginners because you just plant and let them grow.
● You need more control over how the plant grows, which can lead to uneven growth and lower yields.
● Plants may become very large, needing more space than you might have.
● Without training, plants might become too bushy or tangled, which can cause issues with airflow and light penetration, affecting health and yield.
So, if done correctly, training techniques can help experienced growers maximize their plants' potential.
To make sure LST works effectively, start by choosing the right cannabis strain. Some strains respond better to this technique than others.
We’ll discuss which strains are best, review the tools needed for LST, and then cover the step-by-step process.
While this isn’t an exhaustive list, here are some of the most popular cannabis strains that respond well to low-stress training:
Amnesia Haze: Amnesia Haze is famous for its strength and high yields, making it an excellent choice for LST. Being mostly sativa, it provides a balanced high that affects both the body and mind.
This strain tends to grow tall, but LST helps manage its height and encourages bushier growth. Indoors, you can expect 600–650 g/m3 yields, while outdoor plants can yield up to 24 oz per plant.
Sour Diesel: Sour Diesel is known for its high yields (24 ounces per plant outdoors), with practical low-stress plant training techniques. As a Sativa-dominant hybrid, it offers stimulating and uplifting effects. It comes from Chemdawg 91 and Super Skunk crossbreed.
Blue Dream: Blue Dream is from the Blueberry and Super Silver Haze lineages. It is popular among novice and experienced growers for its ease of cultivation and resilience to pests and diseases. Its flexible branches make it ideal for LST and typically yield around 20oz per square meter outdoors. It can grow tall, up to 6 feet.
Northern Lights: Northern Lights is a forgiving strain that responds well to low-stress training. It is a product of the Afghani x Thai lineage, so it naturally grows in a bushier shape. With LST, it can produce impressive yields, often surpassing 25 oz. Per plant outdoors and 18–21 oz./m2 indoors.
Quick Tip:
● Buy high-yield feminized seeds from HomeGrown Cannabis and enjoy free shipping and a germination guarantee!
You need the following supplies for a proper low-stress training process:
1. A young vegetative cannabis plant
2. Plant twisty ties.
3. Soft wire ties (optional): These are only necessary for huge plants and are usually too expensive for smaller plants.
4. Thin wooden or bamboo stakes
5. Small hand drill/scissors
6. A bit of intuitive maneuvering.
You can secure the plant by using similar items like pipe cleaners and coated wire. But avoid using anything sharp or thin, like string, as it can cut into the plant over time.
When preparing for LST, consider the container your plant is in. You don’t need to fill the container all the way to the top.
Instead, leave a few centimeters of space at the top so you can use the rim to tie down branches and stems with a cord.
Alt: using scissors to drill holes around the rim of a cannabis plant container for LST
For plastic containers, you can drill holes around the rim to thread your soft plant cord or rubber-coated wire through, allowing you to tie it to your plant. Fabric grow containers can be set up similarly.
Quick Tip:
● LST is particularly beneficial in confined spaces, such as indoor grow tents, as it allows for better space utilization by controlling plant height and shape. But it can also be done with outdoor plants.
Remember to start low-stress training when your plants have four and six-leaf nodes, ideally during the early or mid-vegetative stage.
At that point, you can follow our beginner-friendly step-by-step guide for cannabis low-stress training:
Alt: Identifying the main stem and branches of a cannabis plant.
Examine your plant to locate the main stem and branches, as these will be the focus of your training. You'll be manipulating these to shape your plant.
Alt: bending the main stem of the cannabis plant
Gently bend the main stem away from its current growth direction. Try to bend only the flexible parts of cannabis stems, which are located near the tips.
Use stakes and ties to secure the stem in its new position, taking care not to damage it.
Alt: branches of the cannabis plant secured with ties.
Apply the same bending and securing technique to the major branches, guiding them to grow outward rather than towards the center of the plant.
You will need to adjust the ties you have used and the positioning of your plants from time to time to accommodate their shape and size changes.
Quick Tip:
● Don’t tie your plants down so tightly that you can’t easily care for or move them! For example, don’t fasten the ties to something fixed on the ground or other objects in the growing area. Instead, secure the ties around the plant container so you can lift and move them as a whole without disturbing the ties.
Alt: Cannabis plant on low-stress training
Throughout the process, it is important to monitor your plants and their health closely. Watch for signs of distress, like discoloration or damage to the stems.
Keep up with low-stress training throughout the vegetative stage. Consistent training helps ensure that your plants receive even light distribution, promoting healthy growth throughout their structure.
Here are some of the advanced LST techniques you can consider:
Let’s now look at what each of these techniques involves in more detail.
An advanced LST technique is the Screen of Green (SCROG) method, which involves placing a net or screen above the plants and weaving their branches as they grow.
This method helps spread out the branches to ensure light and air distribution, creating a uniform canopy.
SCROG is particularly useful in indoor grow spaces with limited room as it maximizes available space and promotes the development of larger buds. However, it has some downsides.
Pros:
● Ideal for taller, branchier Sativa varieties.
● Perfect for grows with limited vertical spaces.
● Provides a high level of control over the plant’s height and light exposure.
Cons:
● involves a long and sometimes extended vegetative growth phase.
● requires an initial setup that can be challenging for a new grower.
● This setup doesn’t make plants easily moveable.
● Requires regular adjustments and manipulation of the plants during training.
Topping is a popular method in which the top of the main stem is cut off to increase light penetration. Like LST, topping should be done when the plant is young.
This technique encourages the plant to grow more lateral branches, resulting in a bushier shape with multiple bud sites and stems.
It’s effective for increasing yields by promoting more flowering sites. However, no cutting technique is actually considered LST. Here are the main advantages and disadvantages of topping:
Pros:
● Promotes an even canopy growth.
● Enhances light penetration and airflow.
Cons:
● It can delay flowering.
● It may stunt growth if not done correctly.
● Open wounds from cutting can expose the plants to disease if not properly managed.
Fimming is similar to topping but involves cutting or pinching some new growth at the top of the plant rather than removing it completely.
This method also boosts the formation of bud sites and dense buds while being less stressful for the plant than topping.
However, fimming is less precise. It can result in a healthy, bushy plant desirable for indoor and outdoor growers.
Pros:
● Produces more branches and colas than topping, potentially leading to higher yields.
● Effectively boost production from a single plant.
● Requires no special tool or equipment.
● Relatively easy to perform by a new grower.
Cons:
● Typically, it doesn’t reduce a plant's height if that is your area of concern.
● Plants may grow in a more unorganized manner after fimming.
We don’t recommend starting LST during the flowering stage of your cannabis plants.
LST should begin when the plant is in the vegetative stage because most of its structure is already established when it reaches flowering.
If you've done LST correctly during the vegetative stage, your plant will grow colas along the flat canopy you've created. This will lead to larger yields from your existing grow lights.
If you accidentally damage a plant and create an open wound, tape it up to keep it closed and support the stem.
The tape acts like a bandage until the plant heals. If you break a stem while bending it, tape it right away. Usually, the stem will recover just fine.
But prevention is better. Avoid using string or anything sharp for LST. Sharp objects can cut into your plants as they grow, which isn't good for them. For more information, check out SFExaminer’s article on growing techniques.
Instead, use soft wire ties, twisty ties, or anything soft and bendable that won’t harm your plants.
Meanwhile, if you plan to use LST on auto-flowering strains, keep in mind that these plants have a short life cycle of 2-3 months.
So start the low-stress training immediately, and don’t consider cutting or topping before starting.
Most of a plant's structure develops during the vegetative growth stage but will still grow a lot in the first two weeks of flowering.
It’s a good idea to continue LST during this phase of your plant's growth but stop once most of the flowers form. This allows it to focus on maturing.
Remember that bending the stems helps the plant develop more colas, which are clusters of leaves at the end of branches where flower buds form. More colas mean more flower buds for you to harvest.
As the number and size of secondary leaves grow, the plant’s ability to produce energy through photosynthesis improves, leading to even more foliage to support the plant.
Quick Tip:
● Some of the signs of harvest time are when you notice vibrant pistils (the hair-like parts on female plants), swollen calyxes (the parts that hold the buds), and sticky trichomes (the tiny glands on the buds).
The impact of low-stress training (LST) on yield varies based on factors like growing conditions, the strain you're using, and your level of experience.
In ideal situations, when done correctly, LST can increase yields by about 40% or even more.
This is because you have allowed the plant to gain improved light exposure and enhanced airflow.
It’s great to see cannabis growers sharing their results online after using Low Stress Training (LST) on their cannabis plants.
You can often learn valuable lessons from these examples, especially if you’re trying LST for the first time. Here are some we’ve come across:
LST done on a cannabis plant.
Credit: r/CannabisGrowers
In the image above, the indoor grower has tied down the fan leaves, which isn’t necessary. Instead, the best approach is to bend the main and secondary stems that come off it.
The grower should let the plant grow and stretch a bit more before training it further. This gives you more to work with.
Each node needs light, so you can bend some of them to the side to prevent everything from being stacked on each other.
ALt: LST done on a young cannabis plant
Credit: r/cannabiscultivation
In this case, it looks like the grower is trying to keep the plants short while also increasing the number of main bud sites. If the goal is to create a bushier plant, the grower might consider topping it several times and spreading it out as it grows.
Another technique to explore is "fimming." If you’re growing photoperiod plants and don’t mind a delay of 1-3 weeks, combining topping or fimming with LST, in this case, can be effective.
As a side note, if you’re growing in a small 2x2 space, like shown in the picture, consider limiting the number of plants to just two. The space often becomes too cramped and thick as the plants flower.
Alt: LST on a young Purple Kush Cannabis Plant
Credit: @MDM_420 on X.
This image shows Low-Stress Training (LST) being done on a Purple Kush cannabis plant.
It might be too soon to determine how well the plants respond to the training. However, it’s a good example of how effective LST can be in cannabis cultivation by simply bending the plants and allowing the limbs to grow sideways.
One common mistake growers make with Low-Stress Training (LST) is pinching or trimming the tops of their plants before starting.
Cutting the plants isn’t part of LST; LST is about bending and shaping the stems.
While pinching off the tops can help the plant grow more evenly, it’s not particularly recommended for autoflowers, as mentioned earlier.
Here are some other common mistakes and best practices to avoid them:
Indeed, low-stress training (LST) is worth the effort if you want higher yields. LST helps plants grow healthier by reducing the risk of mildew and mold. When starting LST, ensure your plants have a few leaf nodes.
We hope our step-by-step guide on LST helps you grow healthier, more productive, and resilient cannabis plants.
ems become hard and woody, making them harder to bend without breaking.
Tying down plants incorrectly Avoid tying them down in a way that makes it hard to tend or move them later. For example, don’t secure ties to anything fixed on the ground or other objects in the growing area.
Parting Thoughts
Indeed, low-stress training (LST) is worth the effort if you want higher yields. LST helps plants grow healthier by reducing the risk of mildew and mold. When starting LST, ensure your plants have a few leaf nodes.
We hope our step-by-step guide on LST helps you grow healthier, more productive, and resilient cannabis plants.
