jmh, if you go with a 2 inch high screen, you're going to be bending them under as soon as the reach it - you want to keep tucking your plants under that screen for several weeks. during those several weeks, your plants will first show sex in the form of pre-flowers. then after a few more weeks, they're actually transition into full on flowering, and once that happens, you want to keep tucking them under for another week or 2 after that. once you're about 2 weeks into ACTUAL flowering (not 2 weeks after they show sex), you should let all the individual flowering tips grow up through the screen. so really, a proper scrog with autoflowers still requires almost daily attention for about 1-2 months, depending on speed of growth and flowering. hope this helps clear things up a little!