Hard cane ,Dend, but yellow leaves

[Oysterwren]

I have a hard cane , phalaenopsis type dendrobium. Biggibum,For three years now it grow a beautiful long flowering spike but it has the same yellow leaves it had when I got it .
I’d keep it cooler and dry in the winter (uk) 10F but it flowers at xmas !! So its warm in its rest period and watered and fertilized .in our summer 25F, (when it does NOTHING. ) Confused.
And so is the plant!

[JDT]

If you post a picture of what you are talking about, hopefully we can help with your confusion!