When is the correct time to apply LST? Gorilla Glue Auto by FastBuds

You can start LST as soon your plant is big enough to stand up and strong enough put up with your interference! :) You don't want to damage any young roots during the early delicate stage, so I would recommend waiting until you have at least a few sets of leaves and then tying off the lower half of the plant in one direction and pulling down the top down and tying that off in the opposite direction to make the middle the new top. the lower tie will prevent you from accidentally pulling on the roots as you bend the plant over. Get yourself some plant ties (I use rubberized "soft" ties which you can cut to the required length) as they're cheap as chips and they make life so much easier than fiddling about with string. Watch a YouTube video on LST if you're not confident - there's loads of tutorials available on there - but just be gentle and you'll be fine. Good luck!