I'm growing subulata along with sandersonii in a terrarium. The temp is maintained at about 70 degrees with a humidity of 80% on average. The photoperiod is 12 hours in winter and 16 in summer. Right now, the photoperiod is 14 hours. My question is... the subulata has not flowered yet this year. It is growing, looks healthy, but still no blooms. The sandersonii sends up flower stalks year around.
Does the subulata need a cool winter dormancy?
Is the photoperiod still too short for it to flower?
Any suggestions or advice would be appreciated.