Topping During Pre-Flower?? Plants too tall, any advice? (pictures included)

Hi everyone, I'm growing in a greenhouse and my girls are getting pretty tall. They're about 6 inches from hitting the roof and at this rate, with at least 8 more weeks to go, they're sure to hit it. They began to pre-flower about 2 weeks ago and have not developed much since. Is it a bad idea to top them at this stage? Keeping in mind I would have to top what looks like the sites that will be top colas.
Will the plant develop new cola sites or am I reducing bud potential?
Either way, something has to be done before they hit the roof, and I cant move them outside, too visible. Any Ideas? Do you think even if I top them they're definitely going to hit the roof anyway? I don't know what to do, Help!!! lol
Thanks!
I'll post a couple pictures so its clear what I'm dealing with!

its going to look like a spider web but i would suggest tyeing down as many of the branches as possible LST,cutting at this point will remove all those bud sites

if you do LST work them early I've found they like to snap later in the evening ,i think the heat and light pull moisture out of the branches

Maybe this is a stupid question, but whats LST? Is it when you bend them down?

yes ................

LST all the way - do not cut. Those branches look perfect for LST - thin and could use more fill-in growth. The problem I think you'll have is where/what to tie to. It looks like your options are other branches and/or the wall (put some screws/nails in the wall and attach to them). Good luck and be careful not to break any branches.

siin82 said:

LST all the way - do not cut. Those branches look perfect for LST - thin and could use more fill-in growth. The problem I think you'll have is where/what to tie to. It looks like your options are other branches and/or the wall (put some screws/nails in the wall and attach to them). Good luck and be careful not to break any branches.

Click to expand...

Yeah, bend that dirty girl over and tie her up. They like it like that.

You'll see all kinds of other growth shoot up then. That's ok. Tie them down too. Don't try to accomplish tieing her all the way down in one night. Bend her over till you think she's ok then let off a little and tie it off.

You'll be fine.