Low-stress training (LST) is an increasingly popular group of cultivation techniques used to enhance cannabis yields by gently manipulating the plant’s growth. This beginner-friendly method typically involves bending and tying branches down to create an even canopy with better light exposure and airflow.
LST methods are often favored for their minimal risk to the plant, making them an accessible option for novice growers. We’ll review some of the benefits and potential drawbacks of LST to help you determine the best approach for your next grow.
What is low-stress (LST) training?
Low-stress training is any gentle plant training method used to manipulate the plant’s shape. It’s performed to break the apical dominance or natural “Christmas tree” shape cannabis plants tend to form as they grow upward. In apical dominance, the top cola gets the most sun and airflow. By bending and training young branches down and outward, you expose more bud sites to light and air, improving your growing conditions across the plant and increasing your overall yield.
With LST, you can effectively grow multiple cannabis plants closer together without overcrowding, which helps optimize your yield per square foot. This keeps the top of the plants at a more uniform height, allowing you to position them closer together. With an even canopy, all plants can receive equal light; this, in turn, minimizes competition for light and helps you ensure that each plant can thrive in its environment.
LST also promotes the growth of lateral branches by encouraging them to grow upward, which creates more bud sites. This increases the number of flowering sites on each plant so you can maximize overall yield without the need for additional vertical space.
When done right, LST helps create an open structure, which means better airflow between plants. Improved airflow reduces the risk of mold and pests, which can become problematic in dense plantings. Similar to the benefits of pruning cannabis plants. It also helps your plants maintain a healthy environment, contributing to overall growth and productivity.
Benefits of low-stress training
LST offers a variety of key advantages for cannabis growers, especially for maximizing yield and improving plant health. Here are some of the main benefits:
Increased yield
As we mentioned, LST helps create an even canopy, allowing for better light distribution across the plant. When all parts of the plant receive equal light, photosynthesis occurs more efficiently throughout the entire plant, leading to the development of numerous flowering sites or colas.
As the plant grows and more light reaches lower branches, those branches can also develop into large, dense colas. The result is a higher total yield; instead of being limited to just the top buds, the plant is able to produce multiple significant colas throughout.
Improved light penetration
LST allows light to penetrate deeper into the plant, which helps lower, smaller buds receive adequate light to promote their growth and increase overall flower production. This method also minimizes the shadow cast by the upper leaves and branches; that way, all parts of the plant can contribute to photosynthesis, which is crucial for robust growth.
Efficient use of space
LST allows for closer plant placement without overcrowding, which is especially beneficial in limited indoor spaces. This efficiency can lead to a higher yield per square foot.
Better airflow
The open structure created by LST allows for better airflow around the plants, which reduces humidity levels and minimizes the risk of mold and pest infestations. This also promotes healthier plants and better yields.
Beginner-friendly
In general, LST is an accessible method for novice growers because it helps them enhance yields without tons of experience or equipment. This makes LST an attractive option for those just starting their cannabis-growing journey.
Types of high-stress training
While LST focuses on gentle techniques, high-stress training (HST) involves more aggressive methods that can stress the plant. Here are some common types of HST:
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- Topping
Topping involves cutting off the main stem just above a node to encourage the plant to develop two main colas instead of one. This promotes bushier growth and can lead to increased yields.
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- Fimming
Fimming is similar to topping, except it involves cutting the new growth in a way that leaves some of the leaves intact. This can result in multiple new growth shoots and a bushier plant.
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- Super cropping
Super cropping involves gently bending and pinching the stems to create slight damage, which encourages the plant to focus energy on repairing the site and producing more flowers. This method can lead to denser colas and improved yields.
When to start LST
Proper LST is all about timing and gentle handling. With this in mind, it’s crucial to start low-stress training early in the vegetative stage when the plant’s stems are still pliable and can be easily guided without snapping. At this point, your plant is actively growing, and its energy can be redirected by carefully bending branches, encouraging a more even, flat canopy.
For most plants, wait until 4-6 nodes are present before training. Nodes are the points along the stem where branches and leaves emerge, and reaching this stage ensures the plant is strong enough to handle the stress of being manipulated. Bending too early, or before the plant has enough nodes, can stunt its growth; on the other hand, waiting too long can make the stems too woody and brittle to bend effectively without damage.
When low-stress training autoflowers, the window to work is even narrower. Because autoflower cannabis strains have a shorter life cycle, it’s essential to begin LST as soon as possible—typically once the plant has 3-4 nodes.
You need to be precise and proactive since autos will start flowering automatically without any change in light schedule, leaving less time to shape the plant’s growth pattern before it diverts its energy toward bud production. Early and gentle LST can help maximize light exposure for autoflowers, but every move must be carefully timed to avoid stressing the plant structure during its brief vegetative phase.
Step-by-step guide to LST
Use this beginner-friendly guide to walk yourself through the entire process of traditional low-stress training, from when to start training to expert tips and tricks.
Remember: It’s important to begin LST at the right time to avoid stressing your plant too much. Start LST when your plant has 4-6 nodes: this indicates that it has established a solid root system and is ready to be trained.
Step one: Gather your materials
Before you begin, make sure you have the following ready:
- Soft plant ties or garden wire
Avoid using anything sharp or rough that might damage the plant’s stems. Soft ties like pipe cleaners or Velcro strips work well as tie-downs for young branches.
- Scissors or pruning shears
For trimming plant material if needed.
- Anchor points
Clips, stakes, or holes near the top of your pot/container to attach your plant ties.
- A plant container with a wide top
This gives you room to spread out your plant as it grows.
Important to remember: Never tie too tightly around stems or branches, as this can cut into the plant and cause damage.
Step two: Identify key branches
Once your plant has 4-6 nodes, choose the main stem and the side branches you want to train. Focus on the tallest branches first; these will naturally dominate the plant’s growth.
Step three: Gently bend and secure
Gently bend the main stem down and away from the center of the plant. Then, secure it with your plant ties, attaching them to an anchor point on your pot/container. Do the same for other tall branches, spreading them out to create an even canopy.
The goal here is to flatten the canopy and expose more bud sites to direct light. Always bend gently and remember you’re guiding the plant, not forcing it.
Step four: Monitor and adjust
As your plant continues to grow, it will naturally bend back toward the light. Check your plant every 1-2 days and adjust the ties to maintain the even spread. If any branches grow taller than others, gently bend and secure them again.
Step five: Continue through the vegetative stage
Throughout the vegetative stage, keep monitoring your plant and adjusting the ties as necessary. You’ll notice that the plant develops more bud sites across the entire canopy rather than just at the top.
Once your plant begins the flowering stage (when you see preflowers forming), you can stop the LST process. The plant’s structure will be mostly set by this point.
LST for autoflowers
Autoflowers require a slightly different approach because of their shorter life cycle and more compact structure. Unlike photoperiod plants, autoflowers have a shorter vegetative stage (often around 3-4 weeks). This means they have less time to recover from stress before entering the flowering stage. As a result, LST must be applied gently and early on, usually when the plant has 3-4 nodes.
Here’s how to effectively apply LST to autoflowers.
Start early
Begin LST as soon as the plant is strong enough, usually at 3-4 nodes. Don’t wait too long, as autoflowers will quickly transition into flowering and may not recover from late stress.
Be gentle
Apply gentle bends to avoid stunting the plant. Autos are less forgiving when stressed, so soft ties and careful bending are keys for success.
FAQ
What’s the screen of green (scrog)?
Scrog is an advanced low-stress training technique. A net with a grid is placed above the plants horizontally. As plants grow, their branches are trained to move across the screen laterally.
What is low-stress training (LST) for cannabis?
Low-stress training weed is an easy cultivation technique that allows growers to manipulate the shape and growth of the plant without causing too much stress or damage. The method involves gently bending and tying down the branches of the cannabis plant to create a more even canopy. LST weed enjoys better light distribution and airflow, which ideally leads to increased yields.
When should I start low-stress training?
Ideally, LST should begin when your cannabis plants are in the vegetative stage—typically around 2 to 3 weeks after germination, or when they have developed several sets of true leaves.
Can you use low-stress training on autoflowers?
Yes, it’s possible to apply low-stress training to autoflower varieties. However, you should begin your LST technique when the autoflowering strains are still young—typically when they have developed 3 or 4 sets of true leaves. This allows them to adapt to the training without significant stress.
Autoflowers are also more sensitive to stress compared to photoperiod strains, so it’s crucial to apply LST autoflower techniques gently. Avoid excessive bending or tying that could damage the plant.
How does low-stress training increase yield?
If done correctly, LST encourages even canopy creation, enhances light distribution, improves airflow, maximizes grow space, and increases bud sites.
What tools are needed for low-stress training?
Soft ties or string for securing branches in their new positions; plant stakes or supports to maintain desired shape; scissors or pruning shears to trim excess growth; plant clips to hold down branches for easy adjustments as the plant grows; measuring tape or a ruler to make sure you have consistent distance and angles when training side branches; and gloves to protect your hands, especially if you have sensitive skin or are working with sharp-edged plants.
Is LST suitable for indoor cannabis growing?
Yes—the LST method is particularly effective for indoor growers. Since indoor grow spaces often have limited vertical height, LST allows growers to keep plants shorter and bushier, maximizing the available vertical space while promoting an even canopy. You can also grow multiple plants closer together without overcrowding when you’re using the low-stress technique, which means you can easily optimize your yield per square foot.
