Is it normal for a branch of a kwanzan cherry tree to be hollow?
We just recently pruned some dead branches from the kwanzan cherry tree in our yard. The branches were hollow inside. Is this normal or is this a sign of disease or age? We think the tree was planted near the time the house was built (1967).
It is common for dead cherry tree branches to have hollow centers. This is a characteristic of the species for dead branches. Rotting interiors is never good, but there is nothing you can do about it.
We notice in the center photo that the stub left when you pruned is not cut back to the 'collar' of the branch. It is too long and when it rots the decay can go into the main trunk. We'd recommend that you cut that stub shorter.
For more about how to prune leaving the branch collar (which is where the pruning cut will heal best), There is a photo of a tree collar and more helpful info in the following pub: http://extension.umd.edu/sites/extension.umd.edu/files/_images/programs/hgic/Publications/HG84_Pruni...