dont start flower

One month ago i put some weeds in flowering. I have different sorts. "Ganja Dwarf" and "Indoor mix" . I am first time grower and i do some mistakes.Ten of my plants was males and show it. Another s start show their female nature.I don't understand why four of my supreme and strongest plants don't show everything.HELP

some plants can take up to 3 weeks to show their sex my friend. but 4 weeks....i dont know. are you sure they arnt showing and youre just not looking at some other structure?

Yes, they may either just be very late showing it or you don't have them in good flowering conditions. You need exactly a 12/12 schedule (a timer is essential because it has to be the exact time every day) and there should be NO light at all during the dark period. If these are met then you are either not seeing it or they are just taking a little longer.

Yes, thank you ,but in same place others start flowering after 5-7 days.I give them 12-12. I give them light also. I try do everything right. Maybe ventilation? It is possible ?

no ventilation wont make the plants not show sex.....its somthing else.

here is a list of things you needed to do to get them to show sex.

12/12 light
water every other day( my personal habit)
make sure humidity is low around 25-40%
Temp must not be higher than 85 degrees F and not below 65
good air circulation
if you are using nutes/fertilizer you should be switching from a nitrogen strong to a phospherus strong nute.

other than that bud i have no idea. if they dont show soon get em out they might be male or hermi and you dont want that