How big is too big

well i think my plants about to begin flowering dont know yet still to early i think the withe hairs are coming but i had to cut a foot off my plant coz it was getting to big its grown back already so i dont want to cut it coz its been under 12/12 for 1 week and i dont know how to tie a six foot plants down can any one help

only a noobie here but from what ive read use like shoe string profile nylone string with loose loops so it doesn't cut into the steam's, dont over do it just enough to maintain you hight and anker down, also dont do it to far down as the laws of pysics and leverage apply. Seen alot of pics where people anker back to the pot base and just drill a whole and tie down on it. I would fan out to get maxium light coverage as well.