I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
It won't kill the tree but will grow out the branches and cause loss of interior branches. The ivy won't want to be exposed to the full sun at the top of the tree. If you want to control it you can cut the ivy vines at an acceptable height on the trunk. The ivy above where you cut the vines will die and the foliage fall off in time.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
Q&A Library Searching Tips