Low Stress Training for Higher Yields
Training plants is a common practice in agriculture that has a history going back thousands of years. Growers can achieve better results by shaping the cannabis plant. This is achieved through two general schools of methodology: LST (Low Stress Training) and HST (High Stress Training). Each has its own benefits, and manufacturers often use both in tandem.
Bending, breaking and cutting a plant can be intimidating for beginners. However, low stress training is the most forgiving form of plant manipulation and has a low margin of error. New gardeners will feel more comfortable with this process, which even experienced gardeners use regularly. The fact is that yields can only be increased with LST alone. LST is the least difficult plant learning technique to learn. The materials needed are minimal and inexpensive.
What is low stress training?
This low-risk, high-reward method involves bending branches down so they grow horizontally instead of vertically. New shoots from horizontal branches will grow vertically and fill the crown area with numerous equally tall branches. LST is a great tool to help control high sativa strains in grow boxes or low ceiling tents.
LST is a common indoor practice. The increase in illumination of the lower branches is more critical than in the open air, where the sun falls on the plant from all sides. Outdoor growers usually focus on supporting heavy branches rather than sculpting the plant, but the LST is a great tool to reduce height if outdoor growing needs to remain incognito.
In both of these methods of preparation, the cannabis plant is subjected to a certain amount of stress. LST (as the name suggests) is not stressful and should not slow down plant growth. HST causes severe stress, which includes cutting the plant and sometimes destroying the cell walls. HST can lead to stunted growth for several days as the cannabis plant is focused on repairing and rebuilding. Both styles are suitable for regular and feminized seeds, but only LST should be used for automatic cannabis strains due to their short growth cycle and limited recovery time.
Why we use LST
Cannabis needs intense lighting to reach its full potential. The light follows an inverse square minimum, which means that the light becomes significantly weaker the farther the measurement (canopy) is from the source. By creating an even canopy, most of the bud areas are in the same plane, and the lighting fixture can be placed closer to them. This can improve a grower's yield because the top of the cannabis plant gets more intense light, which encourages larger buds to grow.
Creating an even crown also destroys a cannabis plant phenomenon called tip dominance, where the central stem grows larger than the side branches. The disruption of apical dominance allows lateral branches to receive more plant growth-stimulating chemicals. When LST is used to train a plant to grow an even crown of side shoots, their size and yield are directly increased.
Other immediate benefits of using LST in the garden include increased airflow and maximizing the interior space of the garden. Densely spaced branches with heavy foliage can create a microclimate in the crown. Stale, stale, warm, and humid air can lead to mold problems. Using LST to distribute branches increases airflow and reduces the risk of mold.
Another advantage is the maximum increase in plant area due to its distribution. This can be achieved by bending and tying branches, but using the SCROG network is also very effective. By directing vertically growing branches into different squares of the SCROG grid, growers can use the entire growing area. When low-stress training is done effectively, a single cannabis canopy can fill an entire 122cm x 122cm grow tent.
Materials Needed for Low Stress Learning
Only a few materials are required to use LST. Growers need something to tie to the branch they want to manipulate and something to attach it to. In the case of SCROG mesh, gardeners will need a mesh that fits the size of the garden or can be cut to any size.
To tie branches, cannabis growers should look for rubber or coated wire. If thin, uncoated metal wire, such as a spiral tie, is used, the metal can cut into the branch as it continues to expand. Quality plant ties will have a protective coating on the wire to avoid this, giving the product strength.
Once the wire is attached, it still needs to be secured somewhere. Most cannabis growers use the sides of the pots as a reference point. However, not all containers are equipped with holes for attaching wire, so manufacturers began to get creative. Usually, holes are drilled into the rim of plastic containers, but an inside tip is to use clips attached to the rim as a fastening point. They can be easily moved to the desired position.
LST training clips have also appeared on the market in recent years. These are plastic parts with a bend in them. They attach to branches by cutting them in place, redirecting growth. One disadvantage is that it will take more as the plant grows outward and turns upward to resume vertical growth.
SCROG nets are usually a one-time item. Branches and buds grow through the mesh, and removing it entirely at harvest can be a clumsy and plant-damaging effort. Trimming the SCROG mesh is common when plants are removed and harvested. For this reason, a polycarbonate/plastic mesh is commonly used. Always properly dispose of excess netting as it can pose a threat to wildlife.
Some growers use rope or twine to secure branches or as SCROG netting. There are better materials to use that are widely available. Rope and twine have the ability to retain moisture. In a humid environment (especially close to the soil line when tying branches), this residual moisture can harbor problematic mold spores, which can then infect your cannabis plants.
If you use rope or twine for the SCROG mesh, small fibers can get stuck in the bumps, which is undesirable. Due to contaminants and increased mold potential, neither rope nor twine is suitable for this purpose. Both of the above problems can be avoided by using optimal materials.
When to Use Low Stress Training
Most of the LST work will be done early in the growing season. The main stem and side branches will be the softest and therefore easier to bend. As branches get wider and have more weight to support, they become thick and woody, making them harder to bend and more likely to break. These branches can also be bent with practice, but it's best to start LST early.
The focus of low stress training is on maintaining a level canopy. After the initial horizontal bends, the branches will resume growth upward towards the light. Regular maintenance is needed to tie these vertical ends down as they continue to grow. Gardeners will continue to work on the LST, shaping the plant until the flowering stage begins.
When flowering begins, cannabis plants are usually placed in SCROG if the grower has not already set up their nets. Branches can be gently bent under the mesh to increase the horizontal footprint. This is usually the last time gardeners use LST or other plant training methods during cultivation.
The cannabis plant must have a well-established root system before embarking on low-stress training or other plant training methods. Experienced growers often wait to begin this work until there are at least five nodes on the plant. It is often best to start LST after transplanting the cannabis plant to its final destination, especially when securing the branches to the pot.
What is the best way to bend branches?
The highest vertical end will often be the most visible bend, as the goal is to align it with the lowest branch tip. With new growth, it is easier to bend, but even with more mature branches, always keep the stem a few cm away from where it joins the main stem.
As the branch slowly bends down, secure this area so that the junction where the branch meets the main stem does not absorb pressure that could break.
Bends can be done gradually; affiliates do not need to reach their final destination immediately. Stubborn branches can be bent lower and lower every day (or hour) until they reach the desired height. It is better to work slowly and gradually than to risk a significant break.
For branches that are not easily flexible, gently squeeze and rub the stem together. Softening the cell walls will make it easier for the branch to bend at that point. However, when using LST, more than one bend point may be required to achieve horizontal growth.
What to do if a branch breaks?
Don't worry, don't panic. If he's still a little attached, there's a good chance he'll be saved. The only materials needed are tape and some time. Before using the tape, return the branch to its original position and minimize open wounds.
Use tape that can stretch as the area grows; Plant tape or even duct tape is a good choice. If a side branch breaks where it attaches to the main stem, wrap the tape underneath it, around the main stem, and back over the broken branch. Do this pattern several times to secure it.
If the branch needs additional support, flexible wire can be temporarily used to fix it. A bamboo stake in the soil can also be used as a support. Be careful in the coming weeks while the wound heals. As a rule, a broken branch in the middle or end of flowering should not be saved due to the healing time.
Can growers use low stress training on automatic varieties?
Yes, LST can be used with automatic cannabis strains. The fear when training an automatic plant is that the recovery time will stop the growth. LST is the most gentle form of plant training and can be done gradually. LST helps to expand the footprint and increase airflow within the medium autoload range. LST is also used to increase the yield of automatic varieties.
LST is a great way to increase cannabis yields, increase light output and maximize the space growers have to work with. This method can be applied to regular, feminized and automatic seeds. This is the most gentle form of plant training and beginners can successfully use LST techniques.
Part of the fun of growing is working with the plants. LST invites the gardener into the grow space and touches his plants regularly. Progress can be checked daily and the final shape is up to the imagination of the gardeners. There are incredible examples of molded plants.
What is your experience with LST in the garden? Is LST a common practice in the home garden, or is it a plant training technique you've been interested in? What plant shape do you want to achieve in order to increase yields? Please let us know your thoughts in the comments.
We hope you enjoyed this plant training article! Craving more information about growing cannabis? Check out our other articles on this topic. Enjoy your time in the space for growing and successful gardening!