We have an approximately ten year old Chinese evergreen elm that my husband fears has suffered damage initially to overwatering the lawn area. It has a large "scar" from the ground starting at a width of 3- or 4-inches to a point at about a 4-foot height. The bark seemed to be peeling away from this area, the base is very wet (sprinkler system) and there appear to be rotting areas at it's base and upward here and there to about one foot. There are also numerous ants traveling up & down along this area.
I know something is seriously wrong, can you offer some suggestion, or have we lost our gorgeous tree?