how long to LST?

Don't just "do stuff" Have a plan. The plan will dictate when and how you train the plant or prune it. e.g. i want 8 colas per plant. While i don't LST, it dictates when i should top and how often (twice). Bending a plant over before it has much axial growth (branches) doesn't do much good. So, make sure enough growth has occured to have some effect. Also, must do so before the stem becomes rigid / more likely to snap while bending it. Working backward from a target canopy - one that is not over-crowded - is the best way to figure this out. There's just too many variables, too many different needs and contexts for each grower. How much space you intend to fill with 1 plant, etc... I'd suggest shooting for about 3 colas per sq ft. More than that rarely improves yields... just causes excess stretching from greater competition for light. So, work backward from space the plant must fill.. this tells you how many colas.. devise a plan to make that happen with the least amount of wasted time and resources.