You need to make a fence around for some years until tree is big enough to take a couple of nibblings.
I have done some with farm wire mesh 5 foot tall, make a loop around and weigh the bottom with a couple of rocks so I can move it easily when needed. I find deer don't test the fence around a tree.
Over the years I prune the branches up to my likings, so I can mow around to the trunk with lawn tractor.