I agree, I don't think the growth cycles of these tuberous Drosera have much
to do with photoperiod, temperature or water. I have noticed that if you
leave one dry when it's coming out of dormancy, it will die back to the
tuber after a short period, and regardless of how much water you give it, it
won't return till next winter.
Occasionally a plant will miss a growth period and remain dormant for
another year - I have no idea why.
Actually I'm amazed at how the plants can survive in the wild. A drought of
2 years or more (which is hardly uncommon in the regions these plants grow)
would surely have to decimate their populations - particularly varieties
which rarely seed.
If someone really wants to alter their growth cycle they had probably best
do it from seed.
Regards,
Paul.