Horticulture Question?

You are a grower of the famous Beutimous flower. It is a long day plant and normally blooms during June (daylength of 15 hours). You have been presented with the proposition to either produce Beutimous flowers in the short days of December (daylength of 9 hours) or die. (You live in a Kingdom where the King is pretty evil.) You cannot lengthen the day with artificial lighting such as metal halide lamps because the King is very cheap and doesn’t want to spend a lot of money. He has provided you with a greenhouse and a dungeon full of candles, which by the way, give off light rich in the red zone (660 nm). Suggest how to get the plants to flower in December. You must be able to explain to the King (an amateur physiologist) how you got the plants to flower in December. Describe how to get the plants to flower in December and how what you suggest works. Since your life depends on it, your suggestion and explanation better be good