jak
Good question. I am glad you asked that question. I myself would not bother
to fill a cavity.
Filling the cavity will not benefit the tree. Do not install drain tubes.
If you do, do not break the boundaries in the tree. Don't wound wall 4. If
you did fill it, fill it with a flexible substance. Foam maybe. Do not use
cement because trees are almost constantly moving in place. The cement
would not be flexible.
Don't forget to treat the system, not just the wound. See proper mulching
he
http://mercury.ccil.org/~treeman/sub3.html

Sincerely,

John A. Keslick, Jr.
Beware of so-called TREE EXPERTS who do not understand TREE BIOLOGY!
www.treedictionary.com
http://mercury.ccil.org/~treeman/
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.
Some people will buy products they do not understand and not buy books that
will give them understanding.

"Jake" wrote in message
...
Ther is a cavity in the trunk of our willow tree, it is about 12
inches long and about four inches deep, can it be sealed up and if so
with what.?
thank you kindly.. I don't want to loose the tree. what type of tree
food does it need./

jak