Part 1: Wildlife Damage
Robinia pseudoacacia (black locust) tree in October.
Photo © 2019 Mary Free
By Mary Free, Certified Extension Master Gardener
Winter and early spring are good times to look at your trees and shrubs with a critical eye to assess their health. The density of the canopy and the appearance of the leaves should be evaluated during the growing seasons to detect signs of disease, and during hot and dry periods for signs of heat stress or dehydration. Surface roots and soil drainage can be checked in any season. However, winter allows an unobstructed view of a deciduous tree trunk, which is central to tree health.
Trees have numerous ways to protect themselves. They can emit chemicals that repel invaders or attract predators to the invaders. Birch trees use the compound betulin, which gives the tree its white color, to reflect sun rays and reduce winter sunscald as well as to ward off invaders. If trees are wounded, they can try to compartmentalize the disease, by isolating or “walling off” the infected area and halting the spread of the infection. But it is bark that provides the first line of protection for a tree. Continue reading →
