Should you seal tree wounds after pruning or storm damage?
For a long time, it was common practice to apply pruning paint or tar sealant to fresh tree wounds, whether from pruning or storm damage S1. The belief was that this would protect the exposed wood from rot, pests, and disease S1. However, this widely held practice is now considered a myth in the gardening community S1.
Why was sealing tree wounds a common practice?
The idea that tree wounds needed sealing stemmed from anthropomorphism, where people projected human biological experiences onto plants S1. Just as a person's cut needs cleaning, antiseptic, and a seal to prevent infection, gardeners assumed trees required a similar "Band-Aid" S1. They worried that exposed heartwood would be vulnerable to wood-boring beetles, airborne fungal spores, or that the tree might "bleed to death" from sap loss S1. By the early 20th century, various petroleum-based asphalt paints and chemical tar compounds were sold as healing aids S1.
What are the problems with using wound sealants?
Despite the intention, these seemingly protective layers often did more harm than good S1. It wasn't until the late 20th century that arborists and tree scientists discovered that routine sealants can impede a tree's natural healing process S1. Instead of protecting, these dressings can trap moisture and create an environment conducive to fungal growth and decay beneath the surface, hindering the tree's ability to compartmentalize and seal off the wound itself S1.
What is the recommended approach for tree wounds?
True tree recovery requires a much simpler approach than applying sealants S1. The current understanding is that trees are better equipped to heal on their own without external dressings S1. Allowing the wound to be exposed to air helps the tree form its own protective barrier, a process known as compartmentalization S1.
