LST (Low Stress Training)

Low Stress Training (LST) is a suite of non-destructive canopy-manipulation techniques in which flexible branches are bent and secured — with soft ties, plant clips, or trellis — to reorient growth horizontally without wounding plant tissue. By flattening the apical shoot, LST equalizes auxin distribution among axillary meristems, breaks apical dominance without meristem removal, and produces an even canopy that maximizes interception of photosynthetic photon flux density (PPFD) at the flower-site stratum. Because phloem and xylem continuity remains intact, LST imposes negligible metabolic cost and can be applied throughout vegetative growth and into early flower. LST is the foundational manipulation underpinning SCROG (Screen of Green) systems and is recommended for autoflowering genotypes, which tolerate stress poorly (Zheng 2021, Handbook of Cannabis Production in Controlled Environments). Etymology: descriptive acronym, North American cultivation forums, early 2000s. Synonyms/slang: tying down, bending, training. → See also: HST, SCROG, Pruning, Topping.