When should I put these girls into flower

You need 3 measurements ***This does not take LST or SCROG into consideration. A. Distance between light and base of the plant B. Light distance recommended for flower C Plant Height You can expect a plant to double in size when you flip. **Sativa or heavy stretchers can even triple in height. Flip before you run out of room A = B + ( C * 2 ) if you know she will only double in height. A = B + ( C * 3 ) to be safe and if you have the height.

depending on strain if you put now it will double or even triple the size, so your height, width, pot size is the answer. i would transplant to main pot and would top them, a bit runners or even clones, tall shape, not bushy Happy Growing !!!

All depends on how much space you have. I usually put mine into flower at 18 inches and they can get up to 4 and some up to 8 foot in the stretch. I don't do lst or anything else, so you need to take into account what method your doing as well

You can put them in flower whenever you want. In my opinion, you don't want to flip until your bud room is 75% full from the vegging plants. The other 25% will be filled in the first few weeks of flower. How much each plant stretches is dependent on genotype, so make sure you research the cultivar(strain) you are growing. I hope this helps.