Low Stress Training and Why to Use it

Produce more flower in a small space

LST or Low Stress Training, is a way of getting more light penetration across the plant, while also increasing air circulation.

One of the challenges of growing cannabis in small spaces is getting enough light to the whole plant. That is because they like a lot of light and tend to be tall and bushy plants, and, very often grown indoors. (Note: why they are best grown indoors is a topic for an upcoming blog post, so stay tuned for that.) Indoor growing means artificual light, which is difficult to use because it often does not reach the lower leaves of the plants. With a bright grow light above, the leaves at the top get plenty of illumination. But the leaves in the middle and bottom do not. Then, the flowers that form on the branches that don’t get enough light are usually pretty small and underdeveloped, with the majority of the flowing happening at the top of the plant.

Low stress training or LST is an easy way to address this problem. It is simply a matter of gently (hence the “low stress” part of the name) bending the main stem until it is more or less level with the ground. When you do this, the lower branches get access to more light and will begin to grow straight up toward the light themselves, creating a more even light distribution across the whole plant.

As a result, you can get big, beautiful flowers on all of the branches, not just the ones at the top. Then, you do not need huge plants to get big harvests.

The key to successful LST is to begin bending and tying down the main stem when it is still green and soft. At that stage, it has much more flexibility and it is easier to get a deeper bend without damaging the stem. If you have a more mature plan that you want to begin using LST on, you can repot it into a larger pot and tilt the plant so that the main stem is not vertical, but more horizontal. Then, continue to bend and tie down the soft new growth on the main stem as it grows.

A cannabis plant photographed from above showing mild LST. The main growth of the plant is in the upper right. The other things that look like plant tops are lower branches that are fully exposed to the light and that will form larger flowers due to this exposure.

There are multiple forms of LST and they all have their place in growing. We recommend using the one that works best for your experience level, your growing space and the final size of the plants you intend to grow.

Using LST you can use less energy in your lighting, because you can keep your lights closer to all parts of the plants. At the same time, you can increase your harvest, because there is a direct correlation between light absobtion and flower production. Just remember to be gentle with the plants and you will not be disappointed!