Morning Glories: As Chrysanthemum, MG is from the group " short day ", 1 by dany12

dany12 wrote:
With Poinsettia it works like this:
You have your poinsettia from last year, it is green and you want it to be a red bract for Christmas.
The short day treatment begins 6 weeks before the fetes.Donc a mid-September (too late for this year!) you put your plant 14 hours of night by 24 hours (per day)
Either you put in the dark from 18 hours in the afternoon until 8 o'clock the next day. And you will have beautiful Christmas Poinsettia.

Here a Japanese website that explains the phenomenon for MG.
If someone understands !!!!!
http://www2.tokai.or.jp/seed/seed/seibutsu4.htm
Poisettia.