We have a dogwood tree that is about 20 years old. It is planted in the exposed edge of the woods and gets full sun for several hours at midday. It is partially surrounded by an azalea and a camellias which were planted about 12 years ago. The azalea is about 4' height and spreads about 12' over the ground. The camellia is about 8' high and and 5' in diameter. They are planted in at the points of a triangle about 15' on a side.

Over the years the bottom branches of the dog wood have die. However the this spring the top is leafed out and has blooms. It has never been a prolific bloomer.

Is this normal for a tree of this type to slowly loose it bottom branches, growing in this type of environment.