I purchase a Russian Olive tree from local nursery 2 years ago, about 12-15 feet tall, this year the branches on the tree are showing signs of dying. Not all of them just some here and there around the tree. What can I do?
You have to find out what, exactly is happening before you can take effective measures. Maybe get somebody there to look at it. Tree expert, garden consultant, somebody going by a title like that.
A good place to start is at the root collar. Check if the tree was planted too deeply, then examine how the roots spread out at the base. Very often we see trees left too long in pots with spiraling roots which eventually girdle the tree. If the base of the trunk has an indentation right at ground level instead of flaring out this is often an indication of a girdling root.