About 12 years ago the city planted maples on the boulevard, I did not know about sun scald and my maple was damaged. Since then I have wrapped the tree every winter. It has healed well and is growing. My question is for how many years do I need to wrap it?
Twelve years of protection should be enough. By then furrowed, rough bark usually begins to replace the smooth bark typical of younger trees.
Here is an excerpt from a University of Minnesota publication that addresses your question:
"Tree wrapping with reflective or light-colored material may be effective in preventing sunscald and bark cracking. The current recommendation for trees that are newly planted is that they should be wrapped for at least two winters. Thin-barked species should be wrapped for several years or until mature bark is established. Regardless of how many winters you wrap your trees, care must be taken to remove the wrapping in the spring. Moisture that collects between the bark and wrapping may provide an infection court for disease when the weather warms up."