In this video, Quinton climbs high up into a mature tree in Shoreham, Victoria, to show us a massive old wound up close. He explains how the tree is callusing to protect itself, why some damaged wood must be removed, and how professional bracing keeps the remaining limbs safe.
The Secret Defenses of Trees: How Callus Wood Works
Trees are the ultimate survivalists. When a branch breaks off in a storm or is pruned by an arborist, the tree immediately goes to work to protect itself. Because they cannot walk away from danger or put a cast on a broken limb, they use two fascinating defense mechanisms:
1. Building the Invisible "Castle Walls" (CODIT)
Arborists use a concept called CODIT (Compartmentalization Of Decay In Trees). Think of it like a castle under siege. When the tree's bark is breached, the tree shuts down internal "gates" around the wound using protective chemical barriers. This stops wood-rotting fungi and pests from spreading up and down the trunk.
2. Growing the Callus "Band-Aid"
Once the internal walls are set, the tree begins growing a thick, rolling ring of bark and wood around the edges of the wound. Over several seasons, this callus wood rolls closer and closer together until it completely closes the gap. This new wood is incredibly strong and helps restore the tree’s structural integrity.
When Nature Needs Help: Bracing vs. Tree Removal
While trees do a great job of sealing small wounds, large injuries can create dangerous weak points. In our featured video from Shoreham on the Mornington Peninsula, Quinton demonstrates how professional arborists decide between saving a tree or removing it:
When Tree Removal is Necessary: If a tree has a massive, deep cavity that goes deep into the trunk, the wood inside may die and rot out completely, leaving a hollow tube. If this tree is near a house or road, the risk of it snapping during a storm is too high, and it must be removed for safety.
When Tree Bracing is the Solution: If the tree has a weak "V-union" (where two trunks grow from the same spot) but the wood is still solid, we can save it! By installing heavy-duty, flexible Yale bracing systems, we can tie the heavy limbs together high in the canopy. This takes the pressure off the weak joint, allowing the tree to continue growing and callusing safely.
Why You Should Never Try to Treat a Tree Wound Yourself
In the past, people used to paint tree wounds with tar or "pruning paint" to seal them. Modern arborist science has proven that this actually traps moisture inside the wound and accelerates rot!
The best way to help a wounded tree is to:
Get a Clean Cut: Ensure any pruning cuts are made cleanly by a qualified arborist, leaving the "branch collar" intact so the tree can callus properly.
Professional Assessment: Have a certified arborist assess deep cracks, cavities, or swollen trunks to ensure the tree is structurally sound.
Leave it to Nature (with structural support): Let the tree seal itself naturally, and install professional cabling or bracing if the limb needs help holding its own weight.