No matter where you live, there will also be a rabbit, mouse, or squirrel waiting to sink its teeth into the succulent bark of a young fruit tree.  Especially in winter when other sources of food are scarce, the damage from rodents can be severe enough to kill your tree.  (Keep branches trimmed; piled snow can bring branch tips within easy reach of hungry animals.)

Construct a rodent guard to protect bark by wrapping a cylinder of wire mesh around the tree trunk.  Or use special tree tape.  Make sure the guard extends into the ground and at least 24 inches up the tree.  Make the cylinder several inches wider than the trunk so animals can't nibble from outside.