What it is
LST stands for "low stress training". You gently bend the main stem and the branches and tie them down (with coated wire or string) so the plant grows wide, like a flat canopy, without cutting anything.
What it's for
When a branch is bent and ends up horizontal, the small branches below "think" they are the tip and grow upward. That way all the tips end up at the same height and the same distance from the light: instead of one big cola and many small ones, you get many even colas.
When
From when the plant has 3 or 4 nodes until the first days of flowering. Since it doesn't cut, it hardly stresses the plant: it is the ideal technique for autoflowers.
How to do it
- Bend the main stem little by little to one side, with your fingers, until it's almost horizontal. If you bend it all at once it snaps (better with the plant unwatered, more flexible).
- Tie it to the edge of the pot with coated wire, without pulling tight.
- Every 2 or 3 days, arrange the tips that go up and spread the branches like a star.
- Keep at it until the canopy is flat and even.
Common mistakes
- Bending all at once and snapping the stem (if it happens, wrap it with tape and it usually heals). Tying too tight and strangling the branch. Forgetting about it: the plant straightens back up on its own within a few days.
Before you start
Every prune or training is a wound: the plant spends energy closing it and adjusting. That is why it is only done with a healthy plant that is growing strong. If it is thirsty, has pests, mold, a deficiency or was just cured, let it recover for a few days first: one more blow to a weak plant can kill it.
▲ Pros
- Flat canopy: light reaches every tip
- Almost no stress: works on autoflowers
🎮 Practice it in UnderGrow
It's done from prune, from veg up to pre-flower. It barely stresses and adds yield (roughly 20 % more grams), also on autoflowers. Slows growth a little for about 2 days (3 on autoflowers). The plant takes up more space sideways. First, check its health and stress: the technique adds its stress all at once and it can kill a plant with low health. Health only goes back up with the stress bar below 20 %.
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