Low Stress Training, or LST, refers to any method of training your cannabis plants without causing them stress in the way that topping or pruning might.
How does the LST Method work?
Topping involves the removal of the growing tip of your plants. This causes the growing tip to split and form two main kolas instead of one. With multiple topping it is possible to turn your two heads into four, four into eight, and so on.
As with most methods of trying to improve the yield of your cannabis plants, LST seeks to make the most efficient use of light. According to the inverse square law, the intensity of light radiating from a point source is inversely proportional to the square of the distance from that source. As far as the cannabis cultivator is concerned this means that the best light is at the top of the plants (if they are lit from above) and the lower branches receive a far poorer quality of light, seriously under achieving their potential.
LST methods usually involve pulling the plant downward to present it in a more lateral way, exposing more of its lower branches to the light and allowing a more equal distribution of light intensity. The increase in bud formation on these branches results in a higher yield per plant, and also a higher yield per watt of light. Meaning more bud for less bucks.
How to Grow Marijuana Using Low Stress Training
Despite being designed to minimize stress on the plants, many growers actually use a combination of LST and topping. The process starts with topping. This involves cutting or pinching out the growing tip of the plant below the end node. By removing the tip, the remaining stump will produce two (or more) new shoots and, once they have grown, these in turn can be topped. Topping can be done any time after around a month of vegetative growth, when the cannabis plant has at least 4 or 5 nodes. Theoretically you could keep topping for as long as the plant is in vegetative growth. But too much topping can stress a plant so most growers restrict it to 2 or 3 times. Topping is a good method on its own to keep your plants short and bushy and will produce several kolas instead of one.