Question
Jim,

I have a walnut in my front yard that seems to be dieing from the top down. The top is rotten and parts of the main trunk at the top have fallen off and it is losing limbs from the top on a daily basis. The tree is about 30' tall now. If I cut the diseased top portion off and leave the healthy bottom portion do you think that the tree will eventually grow back into it's original form? I have noticed that birds have made holes and nested in the top of the diseased trunk as well! Two of the eight other unknown type large trees in my front yard seem to have the same problem. Could it be insect related? Thanks so much for your time!

Answer
I lean toward this being walnut canker, a disease. I suggest that you call the local office of the State Forestry agency and ask one of their Foresters to come take a look-this is a free service in most states. If it is walnut canker there is not much that can be done except pruning out and distroying the infected limbs. An on the ground inspection could tell what can be done.