How to Grow Marijuana with Low Stress Training (LST)

What are Low Stress Training Techniques for Cannabis and Why Use Them?

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. 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.

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.

Having topped your plant, and having several healthy shoots growing vertically, you simply pull back the branches, downwards and outwards. Most growers attach the branches to the pot with strings, although people use everything from wire, to pipe cleaners to retractable lanyards. A slight amount of built intension, such as an elastic band between two lengths of string, can help keep a constant pressure on the branch. You can either attach screws to the pot to tie the string to, or just use some duct tape. It is important that the strings are padded where they meet the plant, so as not to cut into the branch. Don’t be in too much of rush to train them. Slow and steady wins the race. As the plant grows gradually increase tension on the strings. The lower branches of the plant are now exposed to the light and the top branches are lower down, enabling you to have the light nearer to the whole of the plant. Using the low stress training technique will greatly increase your yield.

Of course, you don’t have to top your plant first. It is possible to bend the single growing tip of an untopped plant down and train the plant to grow low, either along the ground or in a circular way around the pot. This works in the same way as a gallery tree that you might see in a forest, where a tree has fallen and its side branches grow vertically to form a row of new trees. If the cannabis plant is trained along the ground by either tying or attaching it with wires, the side branches grow vertically, presenting new growing tips and kolas.

Are All Types of Cannabis Suitable for LST?

Most types of cannabis will adapt to Low Street Training. Indicas are often more favoured because of the improvements that can be made to their generally underproductive side branching. But Sativas respond equally well given plenty of space, and with their naturally strong lateral branching can produce impressive yields. We recommend Dance Hall, Super Lemon Haze and Cream Caramel.

Check out our cannabis strain review guide to find out the origins of your favorite weed.