By Tinatops
United Kingdom 
My well established Greengage Plum has started to loose it's leaves, they are turning yellow as if it's Autumn!
There is plenty of fruit although most have brown scaly patches and done with the hard resign blobs.
We've watered extra in case it's drought as its close to the hedge but it hasn't helped. The fruit is growing with some dropping...are you able to advise what it is and how can we save the tree?
6 Aug, 2016
Answers
There are a few obvious things to check:
Are there any serious breaks in the bark near the base, or sap coming out of the trunk or branches?
Have any weed killers been applied to the lawn about it?
Has the grade been changed around the tree within the last few years?
I hesitate to apply U.S. diagnostics to the UK, but here I would be looking at damage to the trunk, say from borers or string trimmer girdling, or being buried too deep; or damage to the roots by a pervasive fungus infection, such as honey fungus--Texas root rot, over here!
7 Aug, 2016
I have not a clue what is wrong with your greengage but it looks pretty sick to me......My only advice is to keep watering and wait and see what developes next spring. It may recover and be fruitful again.....it may not. Good luck anyway.
7 Aug, 2016