If two of my plants didn't flower and two did can I force the owner two to flower?

[xxsicknessxx]

I planted four plants may 12th I think two flowered and have some bud the other two just keep growing but no flowers. How can I force the two to flower please? Please explain it fully to me because I'll be doing whatever you say. So be careful please. Thank you. Also I've lost track how long do they grow out side? I have only done hydro this is my first try outside next year in planting a lot more but I gotta get my twenty buck for the clone back at least m advise? Want photos?

 

[darvocet21]

I'm not your best source on this one however I would separate them.

 

[dabman]

the only way i know to force flowering is to switch to 12/12 lighting

 

[neversickanymore]

Did you sex them to make sure your only playing with ladies.

 

[Bagseed]

well different genetics might respond slower to the change in photoperiod. so the other two plants might soon get to it. just wait for it I'd say. are your plants female cuttings or from seed? same variety or different?