The flowering time the strain of the plant will decide, vegging longer = more yeild only to the point that you have enough light to provide.Technically speaking you could veg for 9 months and then flower in the regular 9ish weeks and pull 8 pounds off it....if you have the light to do it... the 8 lbs is stupidly excessive in my own case as there is no way I can buy lots of 1000w systems to use together for something like that.
Jack is a VERY LONG flower time like 13 weeks you cannot pick it after 7