Cannabis plants naturally grow in a Christmas tree shape, with one dominant main cola reaching for the light while lower branches stay shaded and underdeveloped. Low stress training, commonly called LST, reshapes the plant by bending and tying down branches so that multiple colas receive equal light exposure. The result is a wider, flatter canopy that produces more bud sites and ultimately more weight at harvest.
Why LST Works
Cannabis plants exhibit apical dominance, meaning the main growing tip produces auxin that suppresses lower branch growth. When you bend the main stem down to the same height as lower branches, the auxin distribution changes. Lower branches begin growing upward with the same vigor as the former main cola. The outcome is multiple tops instead of one, each developing its own cola at harvest.
When to Start
Begin LST when the plant has four to six nodes, typically three to four weeks after sprouting. Stems are flexible and bend without snapping at this stage. Waiting too long makes stems woody and rigid. LST works during the vegetative stage. You can continue into the first week or two of flowering. Avoid bending during mid to late flowering.
Materials
You need soft plant ties or coated garden wire. Avoid string, zip ties, or anything with a sharp edge. Pipe cleaners work in a pinch. You also need anchor points: holes in pot rims, soil stakes, or pot-edge clips. Purpose-built LST clips snap onto stems and hook over pot edges.
Step-by-Step Process
Bend the main stem gently to one side, slowly, supporting near the base. You want a gradual arc. Tie it so the tip is at roughly the same height as the lowest branches. Within a day or two, lower branches will reach toward the light. As they grow, bend each branch outward from center, creating a star pattern viewed from above. Keep the canopy flat and even. Check ties every day or two and adjust as branches grow.
LST for Autoflowers
Autoflowering strains have a fixed life cycle, so recovery time from stress is costly. LST is ideal for autoflowers because it reshapes without slowing growth the way topping does. Start earlier, around the third node. Keep bends gradual. Every day of recovery is a day lost from the short flowering window.
Combining LST with Other Techniques
LST pairs well with topping for photoperiod strains. Top the main stem at the fourth or fifth node, wait for two new tops to grow, then bend them outward. This creates a Y-shape that multiplies cola sites. Defoliation complements LST by removing fan leaves that block light to the interior canopy.
Common Mistakes
Bending stems too aggressively causes snapping. If you hear a crack, wrap with tape and support it. Cannabis heals from partial breaks well. Using ties that cut into stems restricts nutrient flow. Check ties regularly. Starting too late limits effectiveness as stems harden and lower branches cannot catch up before flowering.