Q. Our Chinaberry tree broke off after the winds a few days ago. I saw all this dark wood inside the tree and it was dried out. This tree has withstood way stronger winds than what we just had which concerns me. Is this anything to be concerned about?
A. The inside of any tree, including Chinaberry or Texas Umbrella tree, is virtually dead regardless whether it is healthy or not. This dead area is called the “heartwood” of the tree. The only living part of its trunk is a small cylinder of wood surrounding the heartwood and just under the bark. This is called the “sapwood”.
Heartwood is darker in color than sapwood. Because it is dead, heartwood can rot without damaging the sapwood. This rotting of the heartwood can leave the tree hollow on the inside. But rotting of the heartwood can also make the tree weaker and prone to breakage during strong winds.
As a tree gets bigger it grows in two ways; it grows taller and limbs become longer called primary growth. It also gets "fatter" or bigger in diameter. This growth is called secondary growth. Secondary growth is responsible for sapwood remaining just under the bark as the tree gets “fatter”. As sapwood grows outward it leaves behind the dead heartwood in its interior.
The tree can live without its heartwood but it cannot live without its sapwood. But loss of heartwood can leave the tree weakened. If the tree can cause damage when it breaks, then consider removing it.
The “dryness” of the wood may be "dry rot" as the heartwood is disappearing or rotting away. Frequently interior rotting of the tree is accompanied by soft growths attached to the trunk. These are a type of mushroom called “bracket fungi” or conks and are strong indicators that some form of rotting is occurring.
If you want to keep the tree strong, make sure it receives enough water and fertilize it once a year. If it does not, the tree becomes weaker and much easier to damage during strong winds.