Plant Training: Low-Stress Techniques

Published: February 23, 2022

Low-stress training allows growers to modify and optimize hemp’s inherent qualities with minimal stress to the plant.

LOW-STRESS TRAINING: TAKING CAUTIOUS STEPS TO PRODUCTIVE CULTIVATION

All plants are hardwired to grow towards the light in a botanical survival mechanism called Apical Dominance. Letting plants grow on their own will cause them to get as tall as possible, which means nearly all of the nutrients will be directed toward the main cola, causing lateral buds to remain small and less developed. 

This is the natural way of life for the cannabis plant. 

The Art of Minimal Stress, Great Results 

Otherwise known as LST, Low-Stress Training is a technique that helps manage the natural growth of cannabis, modifying it to make multiple well-developed flowers instead of a single, dominant one. 

The most common of this technique involves bending and tying strategic branches and stems gently and carefully – the “tie-down” method. 

LST is more secure than the High-Stress technique. Using LST decreases the risk of over-stressing the plant, allowing it to adjust to the training measures and adapt more rapidly. 

Through the Years

Low-Stress Training is said to have been discovered by ancient farmers. According to history, the farmers discovered that artificially controlling fruit tree branches and “training” them makes it easier to collect harvests. It also allows the crop to grow heavy fruits on stems that would have otherwise grown in the shade with poor yields.

In modern-day applications, LST encourages the plant to flatten at the canopy, thus providing more uniform access to light and air flow, hence the multiple thriving bud sites. It also allows sugars and the growth hormone, auxin, to distribute more evenly, promoting the growth of more buds.

As a result, this training type is efficient in indoor and outdoor growing for optimizing space, maximizing bud output, and keeping a low crop profile in outdoor cultivation. 

Moreover, it is suited for just about any cannabis strain, including autoflowers and feminized seeds. 

How does LST work

The artificial manipulation of cannabis with LST is designed to overcome the natural tendency of the cannabis plant to grow with apical dominance. 

As a rule of thumb, Low-Stress Training gives its best results when carried out during the vegetative phase – when the stems and shoots are still pliable. The training causes the plant to grow in a circular pattern rather than straight up, so when the plant enters its flowering stage the healthy cola sprout upwards from the now sideways-growing plant. 

Planning Low-Stress Training

Again, the best time to start with LST is in the growth (vegetative) stage of the plant’s life cycle. There should be at least three visible nodes, with the first side branches growing from these nodes. 

Low-Stress Training can also be applied again in the early weeks of the flowering stage to promote light exposure on all the leaves. However, do not attempt this technique on fully grown plants. Their mature stems are too rigid, increasing the risk of damaging them in the process. 

In performing LST, avoid using regular wires or strings that may cut into stems as they grow. Instead, go for any of the following: stretchy plant tape, pipe cleaners, or rubber-coated wire. These options are more gentle on shoots and stems. 

Additional tools to consider may include a hand drill and a pair of scissors. Note: the process can and should only begin when the main stem and branches are long enough to allow a comfortable downward bending. 

Step 1: Anchoring

Once the plant is tall enough and ready for manipulation, drill a series of holes into a close-by sturdy structure using a hand drill. Alternatively, you can make use of tomato rings. These are particularly useful if the plant becomes significantly bigger as it grows. 

The holes or rings will serve as anchor points through which the ties are looped and secured to the shoots. 

Step 2: Bending

Carefully bend the main stem downwards till it runs almost parallel to the ground and is gently secured. Controlling the applied force is crucial at this point to avoid snapping the stem and damaging the plant.

If using wires, do not fix them too tightly on the plant either, as this will cut off nutrient distribution and block circulation. It always helps to have duct tape in hand to remedy any accidents – this will be useful to hold together any snaps or breaks till they heal.

Step 3: Shaping

This is the creative part! Some cannabis growers prefer tying the stem in a circular shape around the attached structure (most often a container) so that as it grows it will coil. While others prefer bending the shoots away from the center of the plant (the main stem), giving the plant a star-like or spider-like shape. 

Either way, the primary idea of LST is to bend the branches downwards, so when the plant tries to grow back up, it forms a broad, fan-like structure that allows excellent light and air penetration. 

Step 4: Maintenance and Check-Ups

LST is a process that lasts throughout the plant’s growth. As new shoots appear, they will need to be bent and tied down, same with the shoots and leaves. 

Plus, as the bent shoots grow, the bends may need to be adjusted periodically to keep the canopy even. Some light defoliation is also advised in the beginning, to maximize light penetration.

An Alternative: Screen of Green

Besides gently bending and tying down branches, there are other effective LST techniques. 

The Screen of Green (ScrOG) is a form of LST that uses a screen to encourage horizontal growth. Its general operation involves gently tucking back branches extending past the screen. This technique inhibits vertical growth and encourages lateral growth; thus, maximizing yields.

While ScrOG is mostly used in indoor growing operations, some forms can be utilized in outdoor operations. 

Below is an overview of how to create a ScrOG operation:

  • Screen Properties: The screen should be sturdy enough to bear the weight of the bent branches and spotted with little squares for the shoots to grow.
  • Installing the Screen: The screen is best installed during the vegetative phase and should be well-secured at each end to a wall or post. It should also be gently and evenly brought down on the canopy, guiding the top branches through the squares in the screen. 
  • Weaving the Plants: The plant should have between 10 to 20 branches stretching through the screen before it is considered due for weaving. 

Starting with the outermost branch, gently pull them outwards and weave them through the screen, looping the branches over and under till you exhaust the excess length. This expands the canopy, ensures the stability of that branch, and allows room for air circulation. 

The more the branches are to be woven, the lesser the available screen space. If your screen maxes out on loop slots, you can always top off the center shoots. 

The top nodes should be cut at a precise angle of 45 degrees – and do not worry about the yield value. With the extra air and light circulation, you might get the doubling effect: one node yielding two, and so on. 

  • Trim away any branch or node that is growing from the light (pointing downwards).
  • Monitor your flowers. 

LST and Autoflowering Seeds

Due to the short life cycle of this flower type, high-stress training techniques are not recommended, as they do not have the luxury of time to recover. Thus, LSTs represent an ideal way to manipulate these flowers and improve yield.

Since autoflowers begin flowering much earlier than regular flowers, LSTs should start as early as possible. 

CONCLUSION

All in all, plant training is an excellent tool in Cannabis sativa production, and selecting the most suitable method for your desired outcomes is the only way to truly optimize your harvest. 

Author: Deborah Agboola, Content Editor at Mariposa Technology

About Mariposa Technology

Putting Power & Profits Into The Farmer’s Hands

At Mariposa Technology, we are developing a revolutionary protocol for rapid, in-field testing of industrial and pharmacological hemp. By utilizing a handheld Raman Spectroscopy device, paired with our proprietary database, we will provide affordable, accurate and immediate test results. Our technology will bring the power of self-testing to farmers at a fraction of the price of traditional laboratory testing while also guaranteeing their digital farming experience optimizes their profits. Moreover, our technology will drastically reduce the carbon footprint of the hemp industry at large.

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