limbs should be trimmed smooth and cavities closed to promote
healing. Openings should be cleaned and shaped to allow drainage.
Wounds are a weak point, if left untreated, they will only
get worse with time. Tree cavities hold water promoting rot
and fungi, and are harbors for insects. Filling cavities in
otherwise healthy trees may help improve appearance, promote
wound closure and prevent water and animals from entering
the hollow. While it will not cure decay, proper cavity treatment
(in combination with regular pruning, feed and insect/disease
control) may help improve a tree's defenses.