The short answer is NO. Many people have seen or heard of wound sealants and wonder if they should be using them for the tree’s health. The tree care industry has done a 180 on this topic, from advocating to discouraging their use, which has confused many. This was a common practice decades ago; old tree care texts recommended it and sealant products are still sold at many garden centers. Many substances had been used from roofing tar to latex house paints. It was believed that using these on trees kept out fungi after a cut exposed its vascular tissues.
Research has since shown that tree cuts need open air to trigger natural wound sealing properties. Trees contain chemicals that inhibit fungi and resist decay in the area where a branch meets the main trunk. This area, called the branch collar, is where we are supposed to make our final pruning cut when removing a branch for this very reason. Therefore, the best way to guard against fungi and decay development is to make accurate and judicious cuts and let them breathe.
Well primarily because they are dead, they become dry and brittle and have a tendency to break off in strong winds. Especially the winds of our Nor’easters in the NorthEast. Also dead stubs and branches can be entryways for fungi and bacteria to enter live healthy wood at the attachment points and spread to other parts of the tree.This is especially a concern if the tree has an aggressive or infectious pest attacking it and/or trees nearby. Lastly, on some species, pruning out dead also will greatly enhance a tidy appearance of your trees, giving them a less ragged and messy appearance.
When weighing whether or not to spend the money to have them pruned out, some Q’s to ask yourself are;