1.Thanks for the suggestion, but white paint will look pretty bad next summer.
Would a cardboard cylinder do as well?
Inexpensive tree wraps are available this time of year to prevent sunscald and
freeze cracks. Painting a tree injury is never a good idea because you can seal
in bacteria or other disease causing organisms.

2.Gee, Ingrid, we hadn't had any winter before I noticed the cracks, except for
two mild frosts. Could it have happened that fast?
Frost is all it takes in a tree that is young or thin skinned to create "frost
cracks." Frost cracks occur when the inner and outer wood in the tree's trunk
expands and contracts at different rates when exposed first to frost, then to
warming.
sed5555