when to flower?

hey, just one quick question.
when should i start the flowering process? should i go by height or by age? i was gonna start flowering around 3 mo., but im not sure. any comments are appreciated.
thanks
smoke on sons

you can flower a plant anywere from a month old or older,i normally flower my plants after 2 month of veg ,i have flower plants 2 weeks old before but you lose out on alot of yeild.

Just like marijuanamat said you can flower pretty much anytime as long as the plants are a decent size. It really just depends on your personal preference as to how big you want them to be before flowering and how long you want to wait.

well dude, take in consideration that after going into flowering, the plant will be 1/2 of its size more tall than before. so just look how tall you want yer baby to grow.