how can i make it flower?

i have a 4 month old outdoor plant and i think its a femal because it has pre flowers and i want to know how can i make it flower already because its around 3ft tall already and i dont want it any bigger
i live in nor cal
i heard if you leave in a dark place for a certain amount of time it will start to flower is this true?

i want to know if i could leave it in my shed 4 a day or two to make it flower then take it back outside can i do that has someone done that

i have not grown outside so how to MAKE it flower short of putting in in you shed for 12 hours n in the sun for 12 hrs your kinda on your own. but if its just the size your worried about i would check out a few threads on topping and top the plant that will almost stop vertical growth and will make your plant bush. i am also a firm believer in super cropping i would check out that also hope i helped