Sorry, I can not type chinese now : T% m8 f8 ]# r' ] 1 g1 H3 Z( l/ ?9 R& g# d/ WBut, I put the poinsettia in a seperate room which should have more than 10hrs black time. Maybe it need more sun light?
at least 10hrs darkness, you can treat it 10~14hrs or longer ,it does not a matter, just a couple of hrs of sun light. and hopefully it can change corlor 3 weeks later till x-mas day.