When to start LST?

Check out my diaries, got LST going at about the same age as yours...It depends, if you are planning to top and scrog then don't LST yet until you have 4 - 10 nodes (8-20 branches) and begin. If you want to LST now then preferably do so. I am LST-ing my plants now in order to get them facing upward for all the nodes to LST again and grow as many nodes as possible and then top whilst in veg. (Warning: you need to twist the stem to keep the nodes growing equally and to expose them to the light without having to defoliate the leaves). I also would suggest bending your stem when its thicker before it becomes wood. OR if you are topping, then top first and then LST would be best for equal height when Scrogging. Good luck!