PRUNING PAINT

Pruning paint is often used on trees and shrubs to cover wounds.
However, research has shown pruning paint to be of LITTLE BENEFIT to the tree or shrub. Insects will not be prevented from infesting a tree, and will attack the wound whether it is sealed or not.Disease organisms will have already infected the cut surface. In fact, pruning paint may actually seal disease organisms inside the wound, preventing weather from affecting the organism.
Pruning paint could be classified as a "placebo" -- making the user feel good but doing little for the plant.
Wounds will heal properly if pruned correctly.
For further information, refer to University of Illinois Publication #U5040, Pruning and Care of Trees and Shrubs.