I have had a pot grown fan trained peach tree against the wall on my patio for the past three years. The first year it cropped heavily, last year less so and suffered from peach leaf curl. I treated it with Bordeaux mixture in the autumn and again this spring. Currently the tree has leaves only on the top few branches and most of the others and the main trunk are producing a red/brown sticky gum which drips to the patio. Can you pleaseadvise?