Is it new @Victoria or do you get it to turn red every year on its own ? My brother has an old one which he covers with a black bag for several weeks in the autumn, and has varying degrees of success.
I have had it for about 15 years or so Michael and it is about three meters tall. It is cut back to about one meter each year about March. You shouldn't cut them after August as that is when they start colouring. It is not a hybrid and I have given cuttings away, they root very easily. We don't do anything special with it ... and certainly don't cover it up and have never seen one here covered. I think it is something odd in the UK or cooler climates.
@Victoria I think the practice of covering them up is to give them more darkness which is said to induce them into turning red.
I understand that is the theory ... but we don't do it here and it colours every year. I am sure they do not in their native Mexico and South America, and even parts of the Southern States. We have night and day too. I just don't understand the theory behind it at all.
If you have a warm greenhouse you can probably get away with it, without covering. But if you bring it into the house or have artificial lighting it will stop or alter the timing of the colouring up of the bracts. I think commercial growers do it, as they are expert at getting the timing exactly right for the Christmas period.
I agree with @pete, it needs short days to turn red and inside a house it gets too much light when the electricity is turned on.
We have short days here too! I think it is more to do with no frost, or virtually none. Mine mostly flowers at the top. During the year it gets shadowed by the Brugmansia, the Honeysuckle/Pandorea over the arch and the outdoor living room so is in the shade often during the Summer heat I see them here (strangely not many. I know of 4/5 others) but they stand proudly alone with nothing near them, are not severely cut back like mine just shaped and bloom all over. I cut mine to get the height. When I planted it, it was alone ... but things grew up around it, as they do.
We haven't had any hard frost here as yet but I doubt one of these would be looking too special if it was growing outside, it would have probably stopped growing at least 2 months ago, so flowering wouldn't happen. The only way to keep them growing here is to give them a warm greenhouse, and if you have any lighting in that greenhouse they wont flower.
That is all fascinating but still curious to me ... and I am glad I am here enjoying mine which I will do till March.
I believe Chrysanthemums go through a similar process, but this time to get them to flower out of season. I'll not mention hemp, ( oh, I just did ) which also flowers according to day length.
Ahh, but you can buy them in pots, flowering pretty much any time during the summer due to the alteration of day length.
