Once the marijuana plants start flowering, should I keep them on the 12/12 light schedule until I harvest? I’ve heard that the length of the light period isn’t quite as important once the flowers begin forming. I feel like any amount of light over 12 hours would make the marijuana plants revert to vegetative state.
Both of your assumptions are true. It’s possible for most varieties to revert to vegetative state with a short darkness regimen. A slight lapse in on/off times won’t negate flowering entirely, but it will have an effect on flower quality. They might end up being small, lanky, or loose depending on how bad the regimen was messed up.