Our mature p. japonicas have acquired a rapidly advancing "infestation". Initially, this spring some of the leaves were spotted. A rapidly advancing black sooty residue covers the leaves and peripheral branches. I hope the attached pics. will give a clearer picture of the problem! Diagnosis, management & prognosis please! Thank you. jim33
Sooty mould, growing on honeydew, which is aphid poo. So either the shrub, or the tree canopy above it if there is any, has a heavy aphid infestation.
