Why is my Bougainvillea losing its leaves?

Garden Experts
In my conservatory — which isn't heated continuously — I have a red Bougainvillea that I cut back strongly in the autumn. It has had new growth for some time now, but lots of leaves are turning black and dropping off. Please could you advise me what I can do about this. It always flowered in the summer before, and it has grown to just below the conservatory roof.

The answer

Without seeing your Bougainvillea, that all sounds to me like the plant has been damaged by frost. It's perfectly understandable that you don't want to heat the entire room continuously. It would therefore be a good idea to drape the plant with fleece if there is a danger of frost, and to provide heating underneath the fleece. You may feel that a heating cable is enough, or perhaps a small greenhouse heater with enough output.