Sounds like a fungal or bacterial infection. I'm not sure there's
much you can do.
Fortunately, Mimosa trees sprout readily from cut stumps, so even if
you cut your tree down, you may get a free replacement if not all of
the remainder is damaged.
"William R. Beatty" wrote:
>> Our 5 year old Mimosa tree has suddenly started to die. The leaves are
> turning brown and falling off. This began about 3 weeks ago and
> approximately 60% of the tree appears to be dead. A small hole at the base
> of the trunk is oozing a foam substance as is the area of the first split of
> the main trunk. It has a sour mashy smell. I'm afraid the whole tree will
> be dead in the next couple of weeks. Does anyone have any idea what might
> be killing the tree?