Low stress training (LST) means gently bending the main stem and branches of a cannabis plant and tying them down horizontally, without cutting anything, to create a flat canopy where every tip sits the same distance from the light. You start when the plant has 3–5 nodes and the stem is still green and flexible, and carry on throughout the vegetative stage until the end of the stretch, around the third week of flowering. All you need is coated wire, a few clips and a pot with anchor points.
In brief
- Goal: tips level under the lamp instead of one central cola shading the rest.
- Start: at 3–5 nodes, usually 2–4 weeks after germination.
- Rhythm: small adjustments every 2–3 days; bent tips turn back up towards the light within a day or two.
- Stop: no new bending of main branches after the third week of flowering.
- It is the training method best suited to autoflowers, because it needs no recovery time.
The principle: a flat canopy
Left alone, cannabis grows in a cone: the main tip dominates and holds back the side branches through its growth hormones (apical dominance). Under an indoor lamp, light intensity drops with distance, so the lower tips receive less light and form small, airy flowers. Bending the stem horizontally takes away the tip's advantage: the side branches climb towards the light and become main tips in their own right.
The result is a flat, table-like canopy in which every tip gets similar light. With panel-style LED lamps, which light a wide area, an even canopy makes better use of the whole grow tent.
| Stage | What to do | How often |
|---|---|---|
| Seedling with 3–5 nodes | First bend: main stem laid horizontal and tied to the pot rim | Once, then check daily |
| Vegetative stage | Spread the side branches outwards like spokes and lower any that stick up | Every 2–3 days |
| First 2–3 weeks of flowering | Bend only the tips that shoot up during the stretch | Every 2–3 days |
| From week 4 of flowering | No new bending; only stakes to support the colas | As needed |
What you need
- Coated garden wire in plastic or rubber: it does not cut into the bark and is easy to reposition.
- LST clips: they hook onto the stem without squeezing it and attach to the pot or a stake.
- Anchor points: the handles of fabric pots, small holes under the rim of rigid pots, or hooks; in a grow tent you can also use the frame poles.
- Stakes in bamboo or plastic to guide long branches.
- Avoid: thin string, bare wire and cable ties, which strangle the stem as it grows.
If you grow in rigid pots, drill the holes before filling them with growing medium: doing it later, with the plant in place, risks damaging the roots.
Bending without snapping: step by step
- Work when the medium has not just been watered: a less turgid stem bends more easily.
- Choose the bending point in the green, flexible part of the stem, a few centimetres below the tip.
- Hold the stem with both hands, one above and one below the bending point, and bend it slowly; if you feel resistance, stop and carry on the next day.
- Tie the branch down with a wide loop of wire that leaves some play between wire and stem.
- Point the main stem to one side and spread the side branches like spokes towards the free corners.
- Every 2–3 days, lower any tips that stick up above the rest and move the ties as the branches lengthen.
- Loosen the wire as the stems thicken.
There is no need to bend to 90° on the first day: two or three passes a few days apart give the same result with far less risk. After each bend the tips turn upwards again: a sign that the plant has accepted its new position.
LST on autoflowers
Autoflowering varieties start flowering on their own after 3–5 weeks, often 3–4, and have little time to recover from a cut such as topping. LST, which does not wound the plant, is therefore the most suitable training method. Start as soon as there are 3–4 nodes, usually between the second and third week, bend gently and finish by week 5–6, when the stretch ends. Do not force it: a stressed autoflower has no time to recover and stays smaller. More in the guide to autoflowering cannabis.
LST with topping, scrog and defoliation
- Topping + LST: topping the plant at the 4th or 5th node gives two main colas; after 5–7 days of recovery you bend them in opposite directions and open up the side branches. Timing and where to cut are in the guide to topping.
- Scrog: this is LST with a horizontal net that holds the branches in place; useful when one or two plants need to fill the whole grow tent. See the guide to scrog.
- Defoliation and lollipopping: under a flat canopy the lower part stays in shade; removing shoots and leaves from the bottom third focuses growth on the lit tips. How and when in the guide to defoliation.
Mistakes to avoid
- Bending too late: after the third week of flowering the stems are woody and the colas already formed; bending them risks snapping them.
- Strangling: a tight or forgotten wire cuts into the bark and restricts sap flow; check the ties every time you work on the plant.
- Too much at once: forcing a bend in one go splits the stem.
- No adjustments: without regular checks the tips climb back up and the canopy becomes uneven again.
- Too many tips in the shade: more tips do not always mean a bigger harvest; those left under the canopy form small flowers and are better removed.
Frequently asked questions
When should you start LST?
When the plant has 3–5 nodes and the stem is still green and flexible, usually 2–4 weeks after germination. Before that the seedling is too fragile; by the end of the vegetative stage the stems begin to turn woody.
Can you do LST on autoflowers?
Yes, and it is the most suitable training method, because it needs no recovery time. Start at 3–4 nodes, bend gently and stop around week 5–6.
What should you do if a branch snaps?
If it is only cracked or kinked, straighten it and wrap it with adhesive tape or grafting tape: it usually heals in about a week, forming a thickened knuckle. If it has come off completely, cut it cleanly with clean scissors.
LST or topping: which should you choose?
LST does not wound the plant and suits beginners and autoflowers better; topping creates more main colas but needs 5–7 days of recovery. On photoperiod plants the two techniques combine well.
Pots in various sizes for anchoring branches are in the Gro.w.LaB pots collection.
Updated on 13 October 2026.