veg as long as you want the longer you veg the larger the plant yeild can potentially be, flowering is normally 8 to 12 weeks some strains flower for almost 4 months , look for info from breeders of your strain
I got 2 ft grow space top to bottom can hold 3 plants i will be doing LST.Would it be safe to veg for around a month in a 1/2 to 2 months then flower? Thnx