1 square foot per plant...

Is one sq.ft. enough space for one plant for the whole three months....or does the plant need more space.....

I'm limited in my experience but I'm going to go out on a limb and say it is dependent on strain, growing method, and how long you let it veg. My plants only need 1 square foot each because I flower pretty early. Your results may vary.

well the pots are usally i square ft and so t dosnt make a differnce

i have 20 in a 3x3, so yes, 1 sq foot should be enough. don't let plants get over 12" before flowering though.