GenetixBayEST. 2009
Training · Beginner · 2 min read

LST: low-stress training

Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.

Grower practice
Draft: awaiting expert review Updated
VegTransitionAny system

Short answer. Bend the main stem and branches outward and down and tie them in place so the side shoots rise to the same height under the light. Nothing is cut, so recovery time is near zero, which makes LST the default for autoflowers and beginners. Start in early veg (3–5 nodes), adjust every 2–4 days, and finish shaping by mid-stretch (around flower week 2–3), when stems stiffen.

Tuck first. LST is the house alternative to stripping leaves. Tuck fan leaves under or behind bud sites and spread branches so every leaf works: leaves are the solar farm for the buds. Stripping within reason doesn't hurt yield, but in the founder's experience tucking helps more, and it's safe on every cultivar; responses to heavy defoliation vary. Tuck vs strip (yield and cannabinoids) is an open GenetixBay trial question (see defoliation).

Why it works

Bending the main stem horizontal reduces its apical dominance (the tip is no longer the highest point), so side branches turn upward and grow out. The result is many tops in the brightest light zone rather than one tall cola shading the rest. Light drives yield [1], and lower, shaded buds in cannabis have lower and less uniform cannabinoid content [2].

How to do it

  1. Use soft plant ties or plastic-coated wire; anchor to the pot rim (drill small holes) or to stakes.
  2. Gently bend the main stem toward the pot edge; flex it between fingers first to make it supple.
  3. Tie branches outward like spokes as they grow; keep the tops level.
  4. Turn the pot or re-tie every few days.
  5. In stretch, tuck tops under a SCROG net or just guide them; stop hard bending.

Numbers that matter

Item Typical
Start 3–5 nodes
Adjust Every 2–4 days
Target canopy evenness Tops within ~10–15 cm (4–6 in) of each other
Last bending Flower week 2–3

Common mistakes

  • Thin wire or string that cuts into stems.
  • Bending too sharply too early and snapping the stem (if it creases, tape it; it usually heals).
  • Starting too late when stems are woody.
  • Forgetting the ties as stems thicken (girdling).

Evidence

The mechanism (gravity and position effects on apical dominance) is Established plant physiology. LST yield benefits are Grower practice; the even-canopy rationale is Supported by light-response and architecture studies [1][2].

Questions this article answers

How do I LST a cannabis plant?

Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.

When should I start low stress training?

Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.

Is LST good for autoflowers?

Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.

Can I LST in flower?

Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.

What do I tie plants down with?

Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.

Sources

  1. Rodriguez-Morrison V, Llewellyn D, Zheng Y, 2021. Cannabis yield, potency, and leaf photosynthesis respond differently to increasing light levels in an indoor environment. Frontiers in Plant Science 12:646020. doi.org/10.3389/fpls.2021.646020
  2. Danziger N, Bernstein N, 2021. Shape matters: plant architecture affects chemical uniformity in large-size medical cannabis plants. Plants 10(9):1834. pmc.ncbi.nlm.nih.gov/articles/PMC8468686/

Related

SupportedIntermediate · Draft

Defoliation and lollipopping: what to remove, when, and the evidence

Lollipopping strips small branches and leaves from the shaded lower third at or near the flip; defoliation removes fan leaves that shade bud sites or block airflow. In a controlled study on large plants, neither defoliation three weeks before harvest nor lower-branch removal changed flower or cannabinoid yield per plant, and defoliation improved cannabinoid uniformity. Stripping within reason doesn't hurt yield, but in the founder's experience tucking helps more: tuck and train first. Whether tucking beats stripping, and whether defoliation raises cannabinoids, is an open GenetixBay trial question.

SupportedBeginner · Draft

Topping: cutting the main tip for more colas

Topping removes the main growing tip above a node so the two shoots below take over, breaking apical dominance and producing a flatter plant with more main colas. Top healthy plants with 4–6 nodes, cut just above the chosen node, and allow 5–10 days of recovery before flipping to flower. In one controlled study, pruning twice (at transplant and at the switch to flower) gave the highest flower and cannabinoid yield per plant.

Grower practiceIntermediate · Draft

SCROG: screen of green

SCROG uses a horizontal net 20–40 cm above the pots to spread a few plants into a flat, even canopy: shoots are tucked under the net through veg and early stretch, then allowed to grow up through it. It suits small rooms and plant-count limits, at the cost of longer veg. Fill about 70–80 % of the net before flipping, since plants stretch to fill the rest.

Grower practiceIntermediate · Draft

HST and supercropping: controlled stem crushing

Supercropping pinches and gently crushes a green stem until the inner tissue softens, then bends it over so the tip sits lower. It is used to tame tall shoots in late veg and early stretch. Done right the stem forms a firm knuckle in a few days. Stem snapping gives better buds in the founder's long experience: *Grower practice*, house-endorsed, though no controlled study has measured a potency gain yet. Every cultivar responds differently.

Grower practiceAdvanced · Draft

Mainlining and manifolding: building a symmetrical plant

Mainlining (manifolding) tops a young plant down to the third node, removes all lower growth, and then tops each arm repeatedly to build a symmetrical hub feeding 8 or 16 evenly matched colas. It produces a very even canopy at the cost of 2–4 extra weeks of veg. It is grower practice with no controlled studies; the closest research found double pruning increased yield per plant.

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