Escallonia leaf spot
I've identified escallonia leaf spot on a fairly old established shrub. I understand that the remedy is to cut back hard, and feed and water. But I'm not clear whether I have to cut out all the affected leaves. If so, then ther will be nothing left at all. It is substantially reduced now and I wonder if it will recover without further drastic action, rather like a rose survives having black spot without having to completely defoliate the plant.
Can anyone please advise me?