veg to flowering

What's the smallest size you would recommend before starting flowering? I ask because I'm probably going to be moving in 3 months, so i'm running out of time to wrap up my grow. I've got 4 plants that are roughly a foot tall. So far no signs of sex.

you can start flowering anytime really... people doing pc grows sometimes do 12/12 from start... not recommended can stress plants to hermie. If your plants arent showing sex its fine- give them 36 hours of darkness before you put them into flower and often they will show sex after the 36 hours of darkness or within a week of 12/12...

with plants roughly a foot tall sounds like your ready.

check out this link for more info bout the 36 hours of darkness technique...
https://www.rollitup.org/indoor-growing/76790-36-hours-darkness-after-veg.html#post887625