We have to respectfully disagree with those within the tree service industry and their so called "New Thinking'' on whether or not to seal a pruned limb. Even a local radio talk show host with degrees out the ying yang on trees and gardening, has succumbed to this utter nonsense. All of them should know better. This is not rocket science nor should it be hard to understand that Water always wins the battle over Wood. The "New Thinking'' proclaims that it is not natural (to seal a pruned cut or seal the point from where a limb has broken off), which is about as ridiculous as thinking it is not natural to use deodorant.. both ideas lead to smelly outcomes.