Have heard of seed and cuts going straight into flower and working{Not with all strains though}. If you have seedlings it would probably be better to wait till they show signs of maturity. Many strains will show sex upon maturity{even in veg} Personally I veg on a 24 hour schedule. In the end I feel it comes down to room available, as most folks don't have room for big pants anyways. You see its the stretch you need to consider. Many strains will stretch when put into flower. This need to be considered as height will likely dictate plant size. Some sativas double in height, while some indicas have no stretch at all. Growing style will also be of importance. Some like to grow sea of green style packing the area with as many plants as will fit. Most often this means smaller plants. There are many variables to consider, but it seems you left most of the info out. Good luck. Peace GS
Changing the color of cannabis one grower at a time.