Marijuana is a plant with copious yields, with very high resistance to stress and moderate needs; However, it is not so obvious that the size of the harvest always meets the needs of the grower. Many techniques have been invented designed to maximize the potential of the cannabis plant and increase production yields.
These techniques are divided into two macro-families: there are techniques that aim to subject the plant to strong stress and are defined as HST – High Stress Training methods ; others, however, defined as Low Stress Training or LST , do not involve invasive interventions on the plant, and aim to modify its shape to favor exposure to light.
HST techniques (topping, Scrog, super cropping, lollipopping, schwazzing) almost always consist of aggressive pruning methods , which push the plant to develop more and to take on a shape and size different from its natural ones. By putting the entire organism on alert, the plant is pushed to develop more and faster. LST techniques, on the other hand, exploit ancient gardening techniques to encourage the assumption of a non-natural shape, which however allows the plant to grow and develop massively, to obtain an abundant harvest. In some Egyptian hieroglyphs dating back to 1400 BC, fig trees are clearly depicted bent and directed to grow horizontally.
However, this technique was then popularized and baptized with the name of palmetta - or espalier - only in the 17th century in France. The apple and pear orchards were planted with palm trees not only to improve the exposure of the plants to the sun, but also to beautify the landscape.
The goal of these cultivation techniques is to alter the chemical balances in plants . If left to grow naturally, the cannabis will choose to produce a main bud that will grow as tall as it can, but this is not optimal for yield or flower quality.
Especially indoors, the lower shoots receive less light than the main bud, which will be the most developed part of the entire plant.
What is the LST technique?
Low Stress Training, or LST, consists of bending and tying the branches of the cannabis plant to modify its shape and optimize its development. There are also other equally valid techniques for giving shape to plants, but they involve pruning the branches and, consequently, cause severe stress. The LST technique can be applied alone or together with aggressive pruning techniques, to further maximize yields (e.g. topping and ScrOG).
The pure discipline requires that only the branches be bent , but the majority of growers also prefer to carry out some pruning to optimize the effects of LST, especially in America. Beyond this, the goal is identical: you manipulate the structure of the plant in order to create bushier plants, rather than letting them grow with the typical Christmas tree structure. The branches are bent to create a flatter apical coverage and favor the development of a greater number of main buds, which will receive light in a greater and more uniform way.
When to adopt it?
Since this is a bend, the branches must still be flexible, so it is necessary to practice LST during the vegetative growth phase . As the weeks pass and the flowering phase begins, branches and stems tend to strengthen, developing a thicker and harder bark. In these cases, LST could be risky and lead to branch breakage, resulting in severe stress for the plant.
The apical buds must be bent so as to remain away from the lamp, so that they can grow without risk of burning. It may happen that the branches break after bending: simply reattach them with a little tape and wait a few days. The wound should heal shortly.
Most growers planning to use LST to maximize yields start bending their plants right away. American growers, for example, often adopt the so-called 4-way LST method: the apical top of the plants is pinched in the early stages of life, when they have only developed two or three stages of leaflets. The 2 new apical branches are bent, as are the 2 lower ones. In this way the plant is stimulated to take on a bushy structure . The vegetative growth phase must be prolonged by a few weeks to allow these three techniques to give the best results.
Those who apply pure LST, however, prefer not to combine it with other techniques, thus avoiding any type of unnecessary stress. In this case, it is necessary to bend the plants after at least 2-3 weeks of vegetative growth , to avoid interfering with their development. In these cases, the main stem is treated like the secondary branches and is directly bent downwards, occupying the lateral spaces. Also in this case it may be necessary to prolong the vegetative growth phase by a few days. Having not been subjected to any pruning, the plants resume their normal growth after a few days.
How you do it?
Low Stress Training is not a difficult technique to implement, but it requires a certain delicacy. You need to bend the branches outward and away from the main stem. The difficult thing is imagining the shape you would like the plant to take and proceeding with the folding according to that pattern.
The typical cannabis bush is perhaps the most common and easiest form for beginners to manage. What you need to do is tie the branches that start from the main body downwards, and then proceed by directing them into the best position to obtain the chosen shape.
The branches must always be treated delicately and before proceeding with tying it is a good idea to try to move them manually, trying to find the right position without exaggerating too much with the bending.
Once you have chosen the angle and position, you need to take a gardening cable and attach the branch to the anchor point. If the vase we have has a thick edge, you can drill holes that will be used as anchoring points . The best knot is the slip knot, which has a sliding eyelet which has the characteristic of tightening following the tension of the rope.
You need to proceed like this until you have tied all the branches in the chosen position.
What are the pros?
The main objective of LST is to keep the vertical development of plants under control and increase their productivity thanks to greater exposure to light . By bending the branches downwards and optimizing the available spaces, exceptional results can be achieved even in small spaces.
Growing plants laterally allows for more large, well-formed buds , thanks to more uniform light coverage. The most creative growers can indulge themselves and create real works of art, rotating the branches in a spiral to obtain even more productive bushy shapes. Furthermore, one of the main advantages of LST is that the plants are subjected to minimal stress and, therefore, will recover in a short time. Normally, in 3-4 days they already resume their normal growth.
Low Stress Training is often thought of as a typical technique for indoor cultivation, but it is also used extensively outdoors. Outdoor growers, especially in colder climates, use LST to obtain bushy and stockier plants , less visible than a plant left to grow freely, but with much more impressive yields. The LST technique is also great for saving crops in an emergency. When plants reach excessive heights and you no longer have space to let them grow, LST is an excellent alternative for controlling size without having to prune. If the plant branches are still flexible, you have time to bend them even during the flowering phase.
And the cons?
No cultivation technique aimed at increasing production yields is without drawbacks. LST requires maintenance and care on the part of the grower, who must arm himself with patience and delicacy. Being a very delicate manual technique, it is not suitable for application to large cannabis plantations, because it would require too much time and work.
On the contrary, it is the perfect technique for the hobby grower, who cares for a few plants for his own personal needs. In this case, LST can prove to be an excellent strategy for growing Cannabis with bonsai dimensions, which are less noticeable and produce copious harvests.
Does it work well with all cannabis strains?
Yes. Unlike many HST techniques, LST also works well with autoflowering strains. Autoflowering hybrids , having a shorter photoperiod than classic plants, do not like high stress techniques, because they require more or less long recovery times, incompatible with the fast growth of the plant. LST, on the other hand, does not require long recovery times from stress, and is also suitable for application on autoflowering varieties.
Indeed, LST is perhaps the best way to increase the yield of an autoflowering strain without risking inconveniences. The only difference is that you need to act quickly and bend the branches of your hybrids as soon as possible, to avoid unwanted branch breakage.
