HST (High-Stress Training)

High-stress training (HST) encompasses any training technique that intentionally wounds, breaks, or removes plant tissue to manipulate growth patterns. The "stress" refers to the plant's wound response, when damaged, cannabis releases stress hormones that trigger compensatory growth, including new branching, denser node spacing, increased trichome production, and stronger cell wall development at injury sites. Common HST techniques: (1) Topping, cutting the apical tip to create two main colas; (2) Fimming, partially cutting the apical tip for 3-4 new colas; (3) Supercropping, pinching and bending branches until the internal fibers crack but the outer skin remains intact, creating knuckle-like swelling; (4) Mainlining, combining topping with strict symmetry to create 8-32 evenly sized colas; (5) Defoliation, strategically removing fan leaves to increase light penetration to lower bud sites; (6) Lollipopping, removing all lower branches and growth to focus energy on upper colas. HST is more aggressive than LST (low-stress training) but produces stronger yield gains and more compact plant structures when executed properly. Critical timing rules: HST should only be performed during vegetative growth, with at least 7-14 days of recovery before flipping to flowering. HST during flowering causes irreversible yield loss and stress-induced hermaphroditism. Autoflowers should generally avoid HST since their fixed lifecycle prevents adequate recovery. The skill requirement is also higher, a poorly executed supercropping move can snap a branch entirely, while improper defoliation can stunt plants for weeks.