Sorry, I can not type chinese now 6 F5 {, w6 @" S6 Z2 x* h4 j- f * }3 F* L" ~' U! k2 D9 O. N; GBut, 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.