A month ago I planted 7 crepe myrtles in our backyard. I have noticed 2 of them have developed near the base 'slits' or 'gashes' in the bark. One of them has 3 small slits or gashes, and the other has at least one. They each are less than 2 inches in length. At first I thought maybe an animal was slashing at the tree, but they look naturally formed to me (i. e.they are relatively clean, not surrounded by scratches or other marks). Is this a problem I should be addressing (such as overwatering or a sign of disease), or is this part of the natural exfoliating process of the bark (or otherwise harmless)?