What is wrong with my Linden Tree?

Question

Folks – Take a look at the trunk of my Linden Tree. Should I be concerned? There are also holes in some of the leaves on the tree as well.

Answer 1

The defective area on the tree trunk appears to be an old wound due to mechanical injury, like from a tractor scrape, or where a secondary trunk has spit off, about five years ago. The callus tissue is rolling over the wounded area from both sides, which is a good sign of tree health and response to wounding.

The foliar canopy appears dense and of good deep green color, indicating good health. The holes in the leaf are unrelated to the wounding and may be due to an insect pest or a shot hole fungus, but I can’t see the holes well from the photos. The pest damage if that’s what it is, appears minimal and not of great concern at this time. The tree will go dormant at which time you can have it sprayed with horticultural oil to suppress overwintering insect pest eggs and nymphs. Inspect the leaves top and bottom as they come out in spring, and through the summer to get early intervention on any pest issues developing. Aphids are common on linden trees.
There is not much you can do about the open wound area except to promote the healing and decay resistance by keeping the tree as healthy as possible with water management and fertilization, which with the adjacent lawn the tree may get adequate or too much of both water and fertilizer.
As the callus tissue rolls and closes over the wound, it will mitigate the potential structural weakness that the wound has created. The exposed heartwood in the center of the trunk may continue to create a decay column and hollow the tree trunk. But as long as there is a thick outer circumference of solid wood, the structural integrity will be maintained.