Whens a good time to start the flowering

I just started a plant and its about 8 inches and nice and leafy but i was wondering if theres a general rule in when to start the flowering ....its almost two weeks old in a couple of days

when you flower will result in how tall the plant is,
if you flower between 10-12" your plant will stay a little smaller, plants generally grow by 3x there height when flowered
hope that helps, i flower for my indoor hydro setup at around 10-12"

tidal is right.
you need to calculate the amount of space you have vertically to grow in. for me i flowered at 1ft. my plants are only almost 2 weeks into flower and they all have already doubled in size.

you need to keep in mind they do become often times 3x the size of the plant when switched to flowering because you can easily out grow your area!!