Hypothetical question about vegging

If a person wanted to grow a monster sized plant 6 feet tall, ABOUT how long would you say they'd need to keep it vegging? For hydro VS soil?

Dude youd be better off clipping off the tops so it grows two more branches, once you do it so many times it starts turning into a bush. and you get way more when you do it that way. You can have a monster plant that six ft tall, but when you got a monster bush, that only about 3 or 4 feet tall with ten times as many branches you will get alot more. To answer your question tho, vegg them until you have enough branches and you get it to the size your happy with and then just cut the light back. You can vegg for as long as you need to, even years mann it wont hurt it. If you turn it into a bush though your plant will be monsterous dude, and then even more monsterous when the buds grow big.