Question
I planted several Antique Rose Bushes (Belinda's Dream) in enriched soil with a drip irrigation system 2 years ago.  Last year and early this spring they were beautiful.  Recently they are developing black spots, leaves and stems are turning brown (and falling off), some buds never open, most open with lots of brown on the petals.  I have dusted them with Rose Dust, used insect spray thinking it might be aphids, but nothing seems to help.

Answer
You have two problems. One is that the rose leaves have a fungal disease called Black Spot and the other problem is an insect called a Rose Midge. These tiny insect  lays it's eggs at the base of the flower buds and when the young hatch, they eat the buds and destroy the flowers. Ortho puts out a good spray that should help with both your problems and it is called  Ortho Rose Defense spray. Just bear in mind that any organic spray needs to be re-applied after a rainfall or if the rose leaves get water on them.