GMSgrowsanswered grow question 3 years ago Autos normally start to flower 4 to 5 weeks in veg. That's why you just let them do their thing with very little stress. When you stress you slow growth. Autos are best done in soiless where you can control the proper ph and ec levels for max growth in veg. You want to get them as big as possible before they start flowering. Cheers