I have a decorative plum tree on its last leg. It's three years young. My wife believes that we overwatered it durning the spring. We first noticed this year that the leaves weren't coming in as it usually does. About a month ago my wife started to do some research about it and came up with we overwatered it. She contacted the nursery where we bought it from and they said that's a good possibility. Let it dry out, apply some Dr. Iron and water it in. Did that without any results. The tree is drier than ever.
Then I noticed carpenter ants taking over the tree. I called back and the nursery told me that it is extremly underwatered and that I need to deep water it twice a month with some kind of root stimulator.
Does this sound about right, or is there anything else I could do to help this dying tree. Thanks for any input.

 

At three years old that tree should have been established enough not to need any additional watering unless you were in a drought. Just from what I read it sounds like the tree has been damaged either mechanically or from insects of some sort. By mechanically I mean something like weedeater damage to the trunk or bark damage from a mower etc. Try calling your local Forestry Department. Around here they have a free service where they will come out and give an opinion as to what they think is wrong. I am not ruling out the fact that you may have over watered but offering other potential causes for you to consider.