Good morning. I am a tree owner who takes care of his trees, though I no longer climb them (I'm too old). I have a beautiful shade tree along the side of my house (Kennett Square, PA / SE Penna., USA) and it has developed a concern. Local people unable to help. I was told that the tree is an American elm. It is quite tall. About 4' up, it has developed a wound that oozes liquid under a reddish/rust colored scab. When I gently push on the scab, you can see liquid. Seems to be a clear liquid. I have been unable to find someone who knows what it is or even if it is something to be concerned about.
Any help/suggestions would be gr8ly appreciated.
Thanx