1-3 weeks you'll see white pistils if they're female....then they will start to show buds starting to form rapidly for 3 weeks or so and then growth will level off......towards the end another burst of growth typically happens, typically in the form of the buds swelling and becoming more resinous..... resin formation and the amount of resin varies from strain to strain. keep an on the trichs w/a magnifier...they will indicate when its time to harvest