Posted: 02/06/2014 at 12:36
PS. The black spots on your roses is a fungal disease too, called (surprise surprise) 'Rose Black Spot'.
I would suggest you remove the affect leaves and burn them and don't allow a build-up of affected leaves around the bushes.....it encourages the spoors to spread.
Interestingly, rose black spot has become more widespread since the air has become cleaner. In the old days when most people had coal fires, it was rare......this is because the sulphur in the air killed those spoors.