force flowering help

hey all, im wanting to flower my babies, they are in the ground so moving them inside at night is out of the question, if i put a black bag over them to get 12/12, how long will i need to do it? will i have to continue it until the are ready to harvest to keep them from going back into veg? or can i stop covering them after a little while and let them finish flowering? or is there any other way to flower them before they are ready? thanks for reading, i await your responses

i asked this question a few days ago on here and someone said you can put a garbage can over them (if the plant is small enough) otherwise you have to make a light-proof tent of some sort. you have to cover them each day and stick tightly to the 12/12 schedule until the actual daylength is close (13/11) otherwise they could go back into veg. state. if your outdoors you're better off to let nature run it's course - you'll get more bud and you don't ahve to go through the hassle of properly covering them each day.