When should sex begin to show ?

I have great white shark and juicy fruit outside in pots . Their about 6 weeks old now. When should I expect to be able to see what sex they are ?

That depends a lot on the strain but in many cases you can see prefowers forming by the time there are 6-8 internodes.

In some strains males will show before females much of the time. In my opinion it is best to look for pistil hairs for confirmation of female sex. Early preflowers can sometimes appear to be male and then pop out a pistil hair so when looking at preflowers key on the pistils and not the balls.

You can sex them very early in veg if you have a hand lens or a good macro mode on your camera.

Thank you. I wanted to start my first grow from seed so I could see how I do. I went with regular non-femenized seed this year. I have approx 15 plants going right now and cant wait to get rid of the males when they appear. So far as far as differences between the strains I do notice some how pretty "stout" stems compared to others of their strain.