We lost another tree branch..& inside it looks like coffee grounds. What is that stuff & is it killing tree?

Question

Old old oak tree.

Answer 1

the coffee grounds is termite, er, 'poo'

call an arborist, forrester or exterminator....your state or town agricultural department is a good place to start    

Answer 2

What you're seeing is rotted wood.  It's an effect, not a cause.

And, yes, I agree with the above answer - certain kinds of trees are prone to rotting from the center outward.  We have Sweet Gum trees and several others down by the creek that are doing this.

Answer 3

The coffee grounds sounds like it may be termites.  Call an arborist - listed in the yellow pages. They can diagnose and possibly save the tree.

Answer 4

You didn't say what kind of tree it is.

Cedars are well known to suffer from Heart rot, this disease weakens the tree so that during a storm it falls over.

This is what nature intended, cedars are known as transition species growing in sand and loose soils.  As it grows, it sheds branches and needles to enrich the soil and thus allow more advanced species take control.  This process is called succession.