Tree diagram from Scientific American (1926), illustrating “A Tree of Electricity.” A bolt of lightning can pass through a tree on the way to the ground. Trees contain lots of water, which is a better electrical conductor than air. The trunk of the tree contains a higher concentration of water, just beneath the outer surface (cambium). When lightning surges through a tree, it causes the water in the tree to boil explosively, which can cause the tree to crack wide open, exploding bark up to 100 feet. The duration of the lightning bolt will determine how destructive it will be to the tree. 

Tree diagram from Scientific American (1926), illustrating “A Tree of Electricity.”

A bolt of lightning can pass through a tree on the way to the ground. Trees contain lots of water, which is a better electrical conductor than air. The trunk of the tree contains a higher concentration of water, just beneath the outer surface (cambium). When lightning surges through a tree, it causes the water in the tree to boil explosively, which can cause the tree to crack wide open, exploding bark up to 100 feet. The duration of the lightning bolt will determine how destructive it will be to the tree.