First time growing autos. How long should it take ...

So many variables will effect flower maturation, that it is hard to be specific, but somewhere between 6 and 16 weeks is in the ball park, then again, roughly 7-10 weeks is about normal.. Things like temps, light intensity, nutrition, growing method, and the biggest factor, genetics, all play a part in the "how long will it take" equation. Harvest at about 90-95% brown pistils and your plant will be at peak THC levels and with peak terpenes too. This will give you the most psychoactive buds, that will not cause you to fall asleep, like what can happen with late picked and over ripe flowers that are close to death - as is the situation once all the pistils have turned brown. At this stage, patience is the key. Hope this helps,........ Organoman.