For centuries, tree care was based on misconceptions, leading to practices that often did more harm than good. Dr. Shigo changed this through meticulous research, proving that trees have their own defense mechanisms and do not heal the same way humans do.
His CODIT model demonstrated that trees respond to wounds by isolating the affected area, rather than regenerating lost tissue like animals. This discovery led to better pruning techniques that minimize damage and promote long-term health.
The CODIT Model: How Trees Defend Themselves
Dr. Shigo’s Compartmentalization of Decay in Trees (CODIT) model changed the way arborists understand tree wounds. Instead of "healing" like animals, trees compartmentalize damage, sealing off infected or injured areas to prevent decay from spreading.
This discovery led to modern pruning techniques that avoid unnecessary cutting and allow trees to naturally protect themselves.
Dr. Shigo spent much of his career debunking common tree care myths. Here are a few misconceptions he corrected through science:
❌ Myth: "Topping a tree makes it grow back stronger."
✅ Fact: Topping weakens a tree by forcing rapid, weak growth. Dr. Shigo warned against this damaging practice.
❌ Myth: "Trees heal like humans when injured."
✅ Fact: Trees do not heal in the way animals do. They seal off wounds to prevent further damage but cannot "repair" lost tissue.
❌ Myth: "Tree wounds should be painted over to protect them."
✅ Fact: Tree paint traps moisture and can promote decay. Proper pruning is the best way to protect tree wounds.