Question
Sir;

We live in southern Arizona and been in our current house for four years.  We have 4 Photinia trees (so I was told) in our backyard, that the previous owner put in years ago. These are about 11 feet high, and are spaced about five feet apart.  They give great shade.  We have never had any problems with them.

Anyway, about 2 months ago, we noticed one of the trees was dropping leaves and remaining leaves were turning brown.  I thought it might be fungus or insects, so I sprayed a light mixture I bought at hardware store.  No difference.  On the advice of a friend (who used to work in a nursery)I put down some ironite and composted bull manure around the dripline, and used a soaker hose for several hours to give it a deep moisture.  I was told by our local Univ. extension gardener I am doing all I can.  I try to deep water once a week (down to 2 feet or so), as the last years here have been very dry.  what is strange (to me) is that not all leaves have fallen off, some still remain but very dry and kinda orange/light brown color.


What is wrong here?  Not enough water or too much?Will this tree come back?  Is there anything else I can do? Thanks you for any assistance.

Joel Turner

Answer
Joel,
From the description, I feel that this tree was attacked by a vascular disease called Fireblight. This disease effects the cambium layer of the tree and can be fatal.
The only treatment I know is to directly inject fungicides into the tree. This would need to be done by a professional applicator who is trained in micro injections.
Fertilize the tree with a low nitrogen fertilizer to try to force some new growth, And continue watering as you have been.
Good luck.
Ed Gulliksen