Low-Stress Training (LST) for Horizontal Growth: How to Grow More, Larger Cola

Cannabis cultivation is an ever-evolving art, with growers constantly seeking new methods to maximize yields while maintaining plant health.  One such example is a technique that has gained popularity among home and commercial growers alike, known as ‘Low-Stress Training (LST)’; this is especially true when focusing on achieving horizontal growth.

This method is effective, gentle on the plant, and can significantly enhance yield and quality without the risks of more aggressive training techniques.

What is Low-Stress Training (LST)?

Low-stress training (LST) is a cultivation technique used to manipulate the shape and structure of cannabis plants without causing them significant stress.  The primary goal is to improve light distribution across the plant’s canopy and promote the growth of multiple main colas[1] rather than a single dominant one.  LST is especially beneficial because it doesn’t involve cutting or topping, making it ideal for new growers or those who want to avoid the risks associated with high-stress training techniques (HST).

Unlike HST methods like topping or supercropping, which can shock the plant and lead to temporary slowdowns in growth, LST encourages healthier and more even development. It’s a non-invasive way to guide the plant’s growth and increase yields by optimizing its ability to capture light.

Why Aim for Horizontal Growth?

Horizontal growth is a crucial aspect of LST because cannabis plants naturally grow vertically, concentrating their energy into a single main cola. By training your plants to grow horizontally, you expose more bud sites[2] to light, which allows for the development of multiple, equally sized colas.  Simply put, the following are the main reasons why horizontal growth is advantageous:

Maximized Light Penetration: When your plant grows horizontally, light can reach lower branches and leaves, ensuring that more parts of the plant receive the energy they need to produce healthy buds.

Increased Yields: By spreading the growth horizontally, multiple colas develop instead of a single dominant bud, leading to higher yields at harvest.

Better Air Circulation: A horizontally trained plant allows for better airflow between branches, reducing the risk of mold, mildew, and pest infestations.

Space Efficiency: Whether growing in a small grow tent or a large outdoor space, horizontal growth allows you to manage your growing area better and optimize it.

Similar Grow Methods

While LST is unique in its low-stress approach, there are other methods aimed at achieving similar results in terms of plant structure and yield optimization:

Topping: Involves cutting the main stem to encourage the growth of multiple colas.  This high-stress technique can lead to recovery delays but can work well in conjunction with LST.

Screen of Green (ScrOG): A method where a screen is used to guide plants horizontally by training branches to grow through the mesh.  ScrOG is often paired with LST to enhance the plant’s canopy management further.

Supercropping: A more aggressive, high-stress technique that involves deliberately bending and slightly damaging stems to force the plant to grow in a more controlled manner.  This is often combined with LST in experienced setups.

Step-by-Step Guide to Implementing Low-Stress Training (LST)

Step 1: Start Early in the Vegetative Stage

The best time to begin LST is when the plant is still in its vegetative stage and has developed around 4-6 nodes (leaf pairs)[3].  Starting early allows you to shape the plant before it hardens, making it easier to manipulate.

Step 2: Secure the Main Stem

Gently bend the main stem down toward the side of the pot, encouraging it to grow horizontally.  Be careful not to snap or damage the stem.  You can use soft ties, garden wire, or even pipe cleaners to secure the stem to the edge of the pot.  Ensure that whatever you use is smooth enough not to cut into the plant.

Step 3: Keep Training as the Plant Grows

As the plant continues to grow, repeat the process for side branches.  Bend and secure them outward, encouraging the plant to form a flat, even canopy.  This will promote the growth of multiple main colas instead of one dominant bud site.

Step 4: Monitor and Adjust Regularly

LST requires regular attention. As the plant grows, continue to adjust and secure new growth to maintain the horizontal shape.  Ensure that the ties aren’t too tight and don’t cut into the plant as it thickens.

Step 5: Flip to the Flowering Stage

Once your plant has developed a healthy, even canopy, you can flip it to the flowering stage by adjusting the light cycle (if growing indoors).  During this phase, your plant will start to stretch.  Continue LST during the early weeks of flowering to maintain the flat canopy and encourage bud growth.

Step 6: Maintain Good Light and Airflow

Ensuring even light distribution across the canopy is crucial during the flowering stage.  Adjust your grow lights so that they cover all of the buds evenly. In addition, good airflow around the plant should be maintained to prevent any issues with humidity or mold.

Common Mistakes to Avoid

1. Applying Too Much Pressure: When bending branches, apply gradual pressure to avoid snapping the stems.  If you accidentally damage a stem, use plant tape to support it while it heals.
2. Neglecting Adjustments: LST requires regular check-ins to ensure that your ties aren’t cutting into the plant and that the canopy remains even.
3. Overwatering: LST can expose more of the plant’s soil, leading to overwatering if you’re not careful.  Be mindful of the plant’s hydration needs, especially in a new setup.

Final Thoughts

Low-stress training (LST) is a powerful tool for cannabis cultivators, especially when aiming for horizontal growth.  By promoting a flat, even canopy, growers can increase their yield, optimize light exposure, and make the most of their grow space.  While it requires regular attention and patience, the rewards of LST are well worth the effort, providing healthier plants and more robust harvests.

Footnotes

[1] Cola: The flowering site of the cannabis plant where buds form. The main cola, also known as the “apical bud,” is the largest flower cluster typically found at the top of the plant.

[2] Bud Sites: Locations on the cannabis plant where flowers (buds) grow. These sites are usually located at the nodes where branches and leaves meet the main stem.

[3] Node: A point on the cannabis stem where leaves, branches, and buds develop.