Hi Martha,
It sounds like it might be the right one.
Island of the Doomed sounds familiar. It appears I am not the only one who was looking for that movie. Found it on the reddit dot com /r/movies website. But, that post was 7 years old.
Blood sucking trees/vines? What movie was this?
"All I can recall of it, was that there was an old house with a big tree outside one of the windows. At night, the tree would extend a limb into the window and suck the blood out of the hapless sleeping victim."
I distinctly remember a woman who stepped out on the back patio of the house and the tree got its way with her. Sucking the blood out, until she looked like a shrunken prune.
That surely frightened me as a little kid. Can you imagine how much more a scene like that with today's special effects would scar a young child's mind.
RZanrico