Our dwarf Japanese red vine maple was full-grown when we moved here 13 years ago. The age of the tree is unknown to us. It has a
10 inch, 1/2 inch deep, break in the bark of the main stem. What should I do? Is the tree healthy? How much longer will it live?
The possibilities are a superficial bark expansion crack (but it sounds like it's too deep for that). The most likely is a water deficit that allows drying of tissues, Or it could be a torsion fracture if the stem is unsupported and has twisted in wind event. Or it can be related to a nutrient deficiency, particularly Calcium, without adequate availability impairs good tissue and cell wall development and wood strength.