You've got it in a very alkline spot, and they traditionally need a somewhat acid soil, I'd try watering with Miracid it may have depleted the nutriants in the soil...also I had a similar problem with one of my trees and when I was cleaning out around it I found that some old landscape fabric had been left on one side when I thought we'd gotten it all out...anyway the ants had made a colony under the fabric as protection from the weather and were eating the roots...once I got the fabric ...»

Is your plant in full sun?

I would fertilize it with Miracle Gro \as it should be more lush for this time of year. In addition please check sprinklers as it is not enough in this heat to just get the leaves wet. If it is not enough volume then the plant stays stressed and drops leaves. Also being so close to the house the heat ratio is microwave-like as the heat radiates off of the wall and the plant dehydrates faster if the water volume is not sufficient.

Is it in full sun as Douglas asks, does it get watered during dry spells?

I would not spray it or fertilize it with anything until I figured out the problem.

Is it possible that it is root bound?

Christine, I would make sure it gets enough water. My sprinklers did OK until the drought which pointed out where I didn't normally provide enough water. Some plants almost died but are doing OK because I figured out the real problem. Adding plant food won't help lack of water.

Perhaps if you had work done in that area some damage was done to the plant's root system as well?