We have a white flowering weeping cherry that I've recently noticed is oozing clear sap (no sign of sawdust) from at least three places about 4' up the trunk. Two sites are along "seams" where the tree's bark is splitting like stretch marks. (One split is the entire height of the trunk.) The other site shows signs that small branches have been clipped from the area close to the top of the trunk/standard. I've read this sapping may be due to cankers and that the tree may heal on its own, OR the cankers may need to be aggressively CUT out. The tree was installed by a previous owner and is likely about 15 years old. It's about 12'-15' tall and wide with a 5.5' trunk/standard. It seems otherwise healthy. We've watered it deeply on a few occasions in the past few weeks to make up for lack of rain. The response of the leaves seem to indicate the water was appreciated. What do you would recommend: Shall we wait and see or dig in? Thank you for your time.