Hi Trish thanks so much for this great video! Mine has developed a black mould on some of the branches - would you recommend pruning those off completely?
Do you mean sooty mould? If so that's an indication there's a sucking insect about. Look over your shrub and treat with a Horticultural oil spray. Sometimes, the sooty mould can be dropping from an infected tree above. But yes, prune off the worst branches. The sooty mould will eventually flake off. If it's not sooty mould though, you will need to identify what it is before treating. When spraying with oil, make sure it's not going to do further damage. Spray a test section initially. Good luck