Why is my river birch not growing leaves on the top half of tree? The tree is about 2 1/2 years old. I live in north western Florida and it only got to freezing a few times last winter. It seems that half of my river birch tree has died. It has started to grow leaves from an offshoot and somewhat on the lower half of the tree. The top branches are brown when I scrape them. The trunk itself is green all the way up. I'm not sure what we can do but could you give us advice on how to save the tree? We really want to try.