Purple Leaf Plum HELP
In early April '07 I a landscaper planted a purple leaf plum in the corner of my backyard, approximately 6-8 feet away from the corner wall. The landscaper included this tree on the existing "drip" irrigation system with two adjustable flow drip lines positioned about 12 inches on either side of the trunk. The tree appeared healthy when planted.
Since that time it has slowly (continuously) lost leaves and remaining leaves always appear dry and brittle. New foliage has sprouted but it quickly dries and eventually falls from the tree. The branches themselves are not brittle. When I break a small end of branch off it appears normal (that is not dry or brittle with normal stringy bark/wood texture inside).
The drip irrigation on this tree (as intitially set by the landscaper) waters every other day for about 20 minutes with the adjustable flow drippers opened rather aggressively. A well around the tree fills with 1"-2" of water. I thought maybe that was too much water and reduced the flow slightly, but it hasn't helped the problem.
Are my dry/falling leaves from too much water, too little water, or from something else? Any help... please?